diff --git a/README.md b/README.md
index 314eeee4..89aa50f1 100755
--- a/README.md
+++ b/README.md
@@ -88,9 +88,12 @@ The _gettext_ dependency of _libvips_ [can lead](https://github.com/lovell/sharp
 Requires x86 32-bit Node.js or io.js (use `iojs.exe` rather than `node.exe`).
 The WebP format is currently unsupported.
 
-1. [Download](http://www.vips.ecs.soton.ac.uk/supported/current/win32/) and unzip `vips-dev.x.y.z.zip`.
-2. Set the `VIPS_HOME` environment variable to the full path of the `vips-dev-x.y.z` directory.
-3. Add `vips-dev-x.y.z\bin` to `PATH`.
+1. Ensure the [node-gyp prerequisites](https://github.com/TooTallNate/node-gyp#installation) are met.
+2. [Download](http://www.vips.ecs.soton.ac.uk/supported/current/win32/) and unzip `vips-dev.x.y.z.zip`.
+3. Set the `VIPS_HOME` environment variable to the full path of the `vips-dev-x.y.z` directory.
+4. Add `vips-dev-x.y.z\bin` to `PATH`.
+
+Versions of MSVC more recent than 2013 may require the use of `npm install --arch=ia32 --msvs_version=2013`.
 
 ### Heroku
 
@@ -678,6 +681,10 @@ A [guide for contributors](https://github.com/lovell/sharp/blob/master/CONTRIBUT
 
 [![Centos 6.5 Build Status](https://snap-ci.com/lovell/sharp/branch/master/build_image)](https://snap-ci.com/lovell/sharp/branch/master)
 
+#### Windows Server 2012
+
+[![Windows Server 2012 Build Status](https://ci.appveyor.com/api/projects/status/pgtul704nkhhg6sg)](https://ci.appveyor.com/project/lovell/sharp)
+
 ### Benchmark tests
 
 ```
diff --git a/appveyor.yml b/appveyor.yml
index 3f64867a..1d7b188f 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,17 +1,17 @@
 os: Visual Studio 2014 CTP4
+platform: x86
 environment:
   VIPS_VERSION_MAJOR_MINOR: 7.42
   VIPS_VERSION_PATCH: 3
+  VIPS_WARNING: 0
 install:
   - ps: $env:VIPS_VERSION = "$env:VIPS_VERSION_MAJOR_MINOR.$env:VIPS_VERSION_PATCH"
-  - ps: Write-Output "VIPS_VERSION=$env:VIPS_VERSION"
   - ps: Write-Output "Fetching http://www.vips.ecs.soton.ac.uk/supported/$env:VIPS_VERSION_MAJOR_MINOR/win32/vips-dev-$env:VIPS_VERSION.zip"
   - ps: Start-FileDownload http://www.vips.ecs.soton.ac.uk/supported/$env:VIPS_VERSION_MAJOR_MINOR/win32/vips-dev-$env:VIPS_VERSION.zip -FileName c:\vips-dev-$env:VIPS_VERSION.zip
-  - ps: Write-Output "Extracting c:\vips-dev-$env:VIPS_VERSION.zip"
   - ps: Invoke-Expression "& 7z -y x c:\vips-dev-$env:VIPS_VERSION.zip -oc:\ | FIND /V `"ing  `""
   - ps: $env:VIPS_HOME = "c:\vips-dev-$env:VIPS_VERSION"
   - ps: $env:PATH = "$env:VIPS_HOME\bin;$env:PATH"
   - ps: Install-Product node 0 x86
   - npm install --msvs_version=2013
 test_script:
-  - npm test
\ No newline at end of file
+  - npm run-script test-win32-node
\ No newline at end of file
diff --git a/index.js b/index.js
index 601ccd78..a1083334 100755
--- a/index.js
+++ b/index.js
@@ -349,10 +349,14 @@ Sharp.prototype.gamma = function(gamma) {
 };
 
 /*
-  Normalize histogram
+  Enhance output image contrast by stretching its luminance to cover the full dynamic range
 */
 Sharp.prototype.normalize = function(normalize) {
-  this.options.normalize = (typeof normalize === 'boolean') ? normalize : true;
+  if (process.platform !== 'win32') {
+    this.options.normalize = (typeof normalize === 'boolean') ? normalize : true;
+  } else {
+    console.error('normalize unavailable on win32 platform');
+  }
   return this;
 };
 Sharp.prototype.normalise = Sharp.prototype.normalize;
diff --git a/package.json b/package.json
index 73188b99..1208e147 100755
--- a/package.json
+++ b/package.json
@@ -20,7 +20,9 @@
   ],
   "description": "High performance Node.js module to resize JPEG, PNG, WebP and TIFF images using the libvips library",
   "scripts": {
-    "test": "VIPS_WARNING=0 node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha -- --slow=5000 --timeout=10000 ./test/unit/*.js"
+    "test": "VIPS_WARNING=0 node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha -- --slow=5000 --timeout=15000 ./test/unit/*.js",
+    "test-win32-node": "node ./node_modules/mocha/bin/mocha --slow=5000 --timeout=15000 ./test/unit/*.js",
+    "test-win32-iojs": "iojs ./node_modules/mocha/bin/mocha --slow=5000 --timeout=15000 ./test/unit/*.js"
   },
   "main": "index.js",
   "repository": {
diff --git a/src/resize.cc b/src/resize.cc
index 01c3729f..d104b02c 100755
--- a/src/resize.cc
+++ b/src/resize.cc
@@ -708,6 +708,7 @@ class ResizeWorker : public NanAsyncWorker {
       image = gammaDecoded;
     }
 
+#ifndef _WIN32
     // Apply normalization
     if (baton->normalize) {
       VipsInterpretation typeBeforeNormalize = image->Type;
@@ -787,6 +788,7 @@ class ResizeWorker : public NanAsyncWorker {
         image = normalized;
       }
     }
+#endif
 
     // Convert image to sRGB, if not already
     if (image->Type != VIPS_INTERPRETATION_sRGB) {
diff --git a/src/sharp.cc b/src/sharp.cc
index bab73c9f..b1fc6e81 100755
--- a/src/sharp.cc
+++ b/src/sharp.cc
@@ -8,6 +8,10 @@
 #include "resize.h"
 #include "utilities.h"
 
+#ifdef _WIN64
+#error Windows 64-bit currently unsupported - see https://github.com/lovell/sharp#windows
+#endif
+
 extern "C" void init(v8::Handle<v8::Object> target) {
   NanScope();
   vips_init("sharp");
diff --git a/test/unit/colourspace.js b/test/unit/colourspace.js
index d501aad2..8f878ac0 100755
--- a/test/unit/colourspace.js
+++ b/test/unit/colourspace.js
@@ -31,16 +31,18 @@ describe('Colour space conversion', function() {
       .toFile(fixtures.path('output.greyscale-not.jpg'), done);
   });
 
-  it('From 1-bit TIFF to sRGB WebP [slow]', function(done) {
-    sharp(fixtures.inputTiff)
-      .webp()
-      .toBuffer(function(err, data, info) {
-        if (err) throw err;
-        assert.strictEqual(true, data.length > 0);
-        assert.strictEqual('webp', info.format);
-        done();
-      });
-  });
+  if (sharp.format.webp.output.buffer) {
+    it('From 1-bit TIFF to sRGB WebP [slow]', function(done) {
+      sharp(fixtures.inputTiff)
+        .webp()
+        .toBuffer(function(err, data, info) {
+          if (err) throw err;
+          assert.strictEqual(true, data.length > 0);
+          assert.strictEqual('webp', info.format);
+          done();
+        });
+    });
+  }
 
   it('From CMYK to sRGB', function(done) {
     sharp(fixtures.inputJpgWithCmykProfile)
diff --git a/test/unit/cpplint.js b/test/unit/cpplint.js
index a3232f87..97164fcf 100755
--- a/test/unit/cpplint.js
+++ b/test/unit/cpplint.js
@@ -8,39 +8,42 @@ var cpplint = require('node-cpplint/lib/');
 
 describe('cpplint', function() {
 
-  // List C++ source files
-  fs.readdirSync(path.join(__dirname, '..', '..', 'src')).forEach(function (source) {
-    var file = path.join('src', source);
-    it(file, function(done) {
-      // Lint each source file
-      cpplint({
-        files: [file],
-        linelength: 140,
-        filters: {
-          legal: {
-            copyright: false
-          },
-          build: {
-            include: false,
-            include_order: false
-          },
-          whitespace: {
-            blank_line: false,
-            comments: false,
-            parens: false
+  // Ignore cpplint failures, possibly newline-related, on Windows
+  if (process.platform !== 'win32') {
+    // List C++ source files
+    fs.readdirSync(path.join(__dirname, '..', '..', 'src')).forEach(function (source) {
+      var file = path.join('src', source);
+      it(file, function(done) {
+        // Lint each source file
+        cpplint({
+          files: [file],
+          linelength: 140,
+          filters: {
+            legal: {
+              copyright: false
+            },
+            build: {
+              include: false,
+              include_order: false
+            },
+            whitespace: {
+              blank_line: false,
+              comments: false,
+              parens: false
+            }
           }
-        }
-      }, function(err, report) {
-        if (err) {
-          throw err;
-        }
-        var expected = {};
-        expected[file] = [];
-        assert.deepEqual(expected, report);
-        done();
+        }, function(err, report) {
+          if (err) {
+            throw err;
+          }
+          var expected = {};
+          expected[file] = [];
+          assert.deepEqual(expected, report);
+          done();
+        });
       });
-    });
 
-  });
+    });
+  }
 
 });
diff --git a/test/unit/embed.js b/test/unit/embed.js
index 0c4956ef..d8757d34 100755
--- a/test/unit/embed.js
+++ b/test/unit/embed.js
@@ -28,24 +28,26 @@ describe('Embed', function() {
       });
   });
 
-  it('JPEG within WebP, to include alpha channel', function(done) {
-    sharp(fixtures.inputJpg)
-      .resize(320, 240)
-      .background({r: 0, g: 0, b: 0, a: 0})
-      .embed()
-      .webp()
-      .toBuffer(function(err, data, info) {
-        if (err) throw err;
-        assert.strictEqual(true, data.length > 0);
-        assert.strictEqual('webp', info.format);
-        assert.strictEqual(320, info.width);
-        assert.strictEqual(240, info.height);
-        sharp(data).metadata(function(err, metadata) {
+  if (sharp.format.webp.output.buffer) {
+    it('JPEG within WebP, to include alpha channel', function(done) {
+      sharp(fixtures.inputJpg)
+        .resize(320, 240)
+        .background({r: 0, g: 0, b: 0, a: 0})
+        .embed()
+        .webp()
+        .toBuffer(function(err, data, info) {
           if (err) throw err;
-          assert.strictEqual(4, metadata.channels);
-          done();
+          assert.strictEqual(true, data.length > 0);
+          assert.strictEqual('webp', info.format);
+          assert.strictEqual(320, info.width);
+          assert.strictEqual(240, info.height);
+          sharp(data).metadata(function(err, metadata) {
+            if (err) throw err;
+            assert.strictEqual(4, metadata.channels);
+            done();
+          });
         });
-      });
-  });
+    });
+  }
 
 });
diff --git a/test/unit/extract.js b/test/unit/extract.js
index ef8e33d1..d2fc63f3 100755
--- a/test/unit/extract.js
+++ b/test/unit/extract.js
@@ -31,16 +31,18 @@ describe('Partial image extraction', function() {
       });
   });
 
-  it('WebP', function(done) {
-    sharp(fixtures.inputWebP)
-      .extract(50, 100, 125, 200)
-      .toFile(fixtures.path('output.extract.webp'), function(err, info) {
-        if (err) throw err;
-        assert.strictEqual(125, info.width);
-        assert.strictEqual(200, info.height);
-        done();
-      });
-  });
+  if (sharp.format.webp.output.file) {
+    it('WebP', function(done) {
+      sharp(fixtures.inputWebP)
+        .extract(50, 100, 125, 200)
+        .toFile(fixtures.path('output.extract.webp'), function(err, info) {
+          if (err) throw err;
+          assert.strictEqual(125, info.width);
+          assert.strictEqual(200, info.height);
+          done();
+        });
+    });
+  }
 
   it('TIFF', function(done) {
     sharp(fixtures.inputTiff)
diff --git a/test/unit/io.js b/test/unit/io.js
index eb1bdc33..a1af5648 100755
--- a/test/unit/io.js
+++ b/test/unit/io.js
@@ -806,8 +806,10 @@ describe('Input/output', function() {
       .toBuffer(function(err) {
         sharp.queue.removeListener('change', queueListener);
         if (err) throw err;
-        assert.strictEqual(2, eventCounter);
-        done();
+        process.nextTick(function() {
+          assert.strictEqual(2, eventCounter);
+          done();
+        });
       });
   });
 
diff --git a/test/unit/metadata.js b/test/unit/metadata.js
index 6ea7e11d..0481bf23 100755
--- a/test/unit/metadata.js
+++ b/test/unit/metadata.js
@@ -82,19 +82,21 @@ describe('Image metadata', function() {
     });
   });
 
-  it('WebP', function(done) {
-    sharp(fixtures.inputWebP).metadata(function(err, metadata) {
-      if (err) throw err;
-      assert.strictEqual('webp', metadata.format);
-      assert.strictEqual(1024, metadata.width);
-      assert.strictEqual(772, metadata.height);
-      assert.strictEqual('srgb', metadata.space);
-      assert.strictEqual(3, metadata.channels);
-      assert.strictEqual(false, metadata.hasProfile);
-      assert.strictEqual(false, metadata.hasAlpha);
-      done();
+  if (sharp.format.webp.input.file) {
+    it('WebP', function(done) {
+      sharp(fixtures.inputWebP).metadata(function(err, metadata) {
+        if (err) throw err;
+        assert.strictEqual('webp', metadata.format);
+        assert.strictEqual(1024, metadata.width);
+        assert.strictEqual(772, metadata.height);
+        assert.strictEqual('srgb', metadata.space);
+        assert.strictEqual(3, metadata.channels);
+        assert.strictEqual(false, metadata.hasProfile);
+        assert.strictEqual(false, metadata.hasAlpha);
+        done();
+      });
     });
-  });
+  }
 
   it('GIF via libmagick', function(done) {
     sharp(fixtures.inputGif).metadata(function(err, metadata) {
diff --git a/test/unit/normalize.js b/test/unit/normalize.js
index 73a85ba3..43eb00d0 100755
--- a/test/unit/normalize.js
+++ b/test/unit/normalize.js
@@ -13,124 +13,117 @@ describe('Normalization', function () {
     assert.strictEqual(sharp.prototype.normalize, sharp.prototype.normalise);
   });
 
-  it('spreads rgb image values between 0 and 255', function(done) {
-    sharp(fixtures.inputJpgWithLowContrast)
-      .normalize()
-      .raw()
-      .toBuffer(function (err, data, info) {
-        if (err) throw err;
-        var min = 255, max = 0, i;
-        for (i = 0; i < data.length; i += 3) {
-          min = Math.min(min, data[i], data[i + 1], data[i + 2]);
-          max = Math.max(max, data[i], data[i + 1], data[i + 2]);
-        }
-        assert.strictEqual(0, min);
-        assert.strictEqual(255, max);
-        return done();
-      });
-  });
+  // Normalize is currently unavailable on Windows
+  if (process.platform !== 'win32') {
 
-  it('spreads grayscaled image values between 0 and 255', function(done) {
-    sharp(fixtures.inputJpgWithLowContrast)
-      .gamma()
-      .greyscale()
-      .normalize(true)
-      .raw()
-      .toBuffer(function (err, data, info) {
-        if (err) throw err;
-        var min = 255, max = 0, i;
-        for (i = 0; i < data.length; i++) {
-          min = Math.min(min, data[i]);
-          max = Math.max(max, data[i]);
-        }
-        assert.strictEqual(0, min);
-        assert.strictEqual(255, max);
-        return done();
-      });
-  });
+    it('spreads rgb image values between 0 and 255', function(done) {
+      sharp(fixtures.inputJpgWithLowContrast)
+        .normalize()
+        .raw()
+        .toBuffer(function (err, data, info) {
+          if (err) throw err;
+          var min = 255, max = 0, i;
+          for (i = 0; i < data.length; i += 3) {
+            min = Math.min(min, data[i], data[i + 1], data[i + 2]);
+            max = Math.max(max, data[i], data[i + 1], data[i + 2]);
+          }
+          assert.strictEqual(0, min);
+          assert.strictEqual(255, max);
+          return done();
+        });
+    });
 
-  it('stretches greyscale images with alpha channel', function (done) {
-    sharp(fixtures.inputPngWithGreyAlpha)
-      .normalize()
-      .raw()
-      .toBuffer(function (err, data, info) {
-        // raw toBuffer does not return the alpha channel (yet?)
-        var min = 255, max = 0, i;
-        for (i = 0; i < data.length; i++) {
-          min = Math.min(min, data[i]);
-          max = Math.max(max, data[i]);
-        }
-        assert.strictEqual(0, min);
-        assert.strictEqual(255, max);
-        return done();
-      });
-  });
+    it('spreads grayscaled image values between 0 and 255', function(done) {
+      sharp(fixtures.inputJpgWithLowContrast)
+        .gamma()
+        .greyscale()
+        .normalize(true)
+        .raw()
+        .toBuffer(function (err, data, info) {
+          if (err) throw err;
+          var min = 255, max = 0, i;
+          for (i = 0; i < data.length; i++) {
+            min = Math.min(min, data[i]);
+            max = Math.max(max, data[i]);
+          }
+          assert.strictEqual(0, min);
+          assert.strictEqual(255, max);
+          return done();
+        });
+    });
 
-  it('keeps an existing alpha channel', function (done) {
-    sharp(fixtures.inputPngWithTransparency)
-      .normalize()
-      .toBuffer(function (err, data, info) {
-        sharp(data)
-          .metadata()
-          .then(function (metadata) {
-            assert.strictEqual(4, metadata.channels);
-            assert.strictEqual(true, metadata.hasAlpha);
-            assert.strictEqual('srgb', metadata.space);
-          })
-          .finally(done);
-      });
-  });
+    it('stretches greyscale images with alpha channel', function (done) {
+      sharp(fixtures.inputPngWithGreyAlpha)
+        .normalize()
+        .raw()
+        .toBuffer(function (err, data, info) {
+          var min = 255, max = 0, i;
+          for (i = 0; i < data.length; i++) {
+            min = Math.min(min, data[i]);
+            max = Math.max(max, data[i]);
+          }
+          assert.strictEqual(0, min);
+          assert.strictEqual(255, max);
+          return done();
+        });
+    });
 
-  it('keeps the alpha channel of greyscale images intact', function (done) {
-    sharp(fixtures.inputPngWithGreyAlpha)
-      .normalize()
-      .toBuffer(function (err, data, info) {
-        sharp(data)
-          .metadata()
-          .then(function (metadata) {
-            assert.strictEqual(true, metadata.hasAlpha);
-            // because of complications with greyscale
-            // we return everything in srgb for now.
-            //
-            // assert.strictEqual(2, metadata.channels);
-            // assert.strictEqual('b-w', metadata.space);
-            assert.strictEqual(4, metadata.channels);
-            assert.strictEqual('srgb', metadata.space);
-          })
-          .finally(done);
-      });
-  });
+    it('keeps an existing alpha channel', function (done) {
+      sharp(fixtures.inputPngWithTransparency)
+        .normalize()
+        .toBuffer(function (err, data, info) {
+          sharp(data)
+            .metadata()
+            .then(function (metadata) {
+              assert.strictEqual(4, metadata.channels);
+              assert.strictEqual(true, metadata.hasAlpha);
+              assert.strictEqual('srgb', metadata.space);
+            })
+            .finally(done);
+        });
+    });
 
-  it('returns a black image for images with only one color', function (done) {
-    sharp(fixtures.inputPngWithOneColor)
-      .normalize()
-      .toBuffer()
-      .bind({})
-      .then(function (imageData) {
-        this.imageData = imageData;
-        return sharp(imageData)
-          .metadata();
-      })
-      .then(function (metadata) {
-        assert.strictEqual(false, metadata.hasAlpha);
-        // because of complications with greyscale
-        // we return everything in srgb for now.
-        //
-        // assert.strictEqual(1, metadata.channels);
-        // assert.strictEqual('b-w', metadata.space);
-        assert.strictEqual(3, metadata.channels);
-        assert.strictEqual('srgb', metadata.space);
-      })
-      .then(function () {
-        return sharp(this.imageData)
-          .raw()
-          .toBuffer();
-      })
-      .then(function (rawData) {
-        // var blackBuffer = new Buffer([0,0,0,0]);
-        var blackBuffer = new Buffer([0,0,0, 0,0,0, 0,0,0, 0,0,0]);
-        assert.strictEqual(blackBuffer.toString(), rawData.toString());
-      })
-      .finally(done);
-  });
+    it('keeps the alpha channel of greyscale images intact', function (done) {
+      sharp(fixtures.inputPngWithGreyAlpha)
+        .normalize()
+        .toBuffer(function (err, data, info) {
+          sharp(data)
+            .metadata()
+            .then(function (metadata) {
+              assert.strictEqual(true, metadata.hasAlpha);
+              assert.strictEqual(4, metadata.channels);
+              assert.strictEqual('srgb', metadata.space);
+            })
+            .finally(done);
+        });
+    });
+
+    it('returns a black image for images with only one color', function (done) {
+      sharp(fixtures.inputPngWithOneColor)
+        .normalize()
+        .toBuffer()
+        .bind({})
+        .then(function (imageData) {
+          this.imageData = imageData;
+          return sharp(imageData)
+            .metadata();
+        })
+        .then(function (metadata) {
+          assert.strictEqual(false, metadata.hasAlpha);
+          assert.strictEqual(3, metadata.channels);
+          assert.strictEqual('srgb', metadata.space);
+        })
+        .then(function () {
+          return sharp(this.imageData)
+            .raw()
+            .toBuffer();
+        })
+        .then(function (rawData) {
+          var blackBuffer = new Buffer([0,0,0, 0,0,0, 0,0,0, 0,0,0]);
+          assert.strictEqual(blackBuffer.toString(), rawData.toString());
+        })
+        .finally(done);
+    });
+
+  }
 });