diff --git a/.appveyor.yml b/.appveyor.yml
new file mode 100644
index 00000000..75db69e3
--- /dev/null
+++ b/.appveyor.yml
@@ -0,0 +1,28 @@
+build: off
+
+init:
+  - git config --global core.autocrlf input
+
+install:
+  - SET JAVA_HOME=C:\Program Files\Java\jdk1.8.0
+  - SET PATH=%JAVA_HOME%\bin;%PATH%
+
+  - ps: |
+      Add-Type -AssemblyName System.IO.Compression.FileSystem
+      if (!(Test-Path -Path "C:\sbt" )) {
+        (new-object System.Net.WebClient).DownloadFile(
+          'https://github.com/sbt/sbt/releases/download/v1.1.5/sbt-1.1.5.zip',
+          'C:\sbt-bin.zip'
+        )
+        [System.IO.Compression.ZipFile]::ExtractToDirectory("C:\sbt-bin.zip", "C:\sbt")
+      }
+  - SET PATH=C:\sbt\sbt\bin;%PATH%
+  - SET SBT_VER=1.1.5
+  - SET SBT_OPTS=-XX:MaxPermSize=2g -Xmx4g -Dfile.encoding=UTF8 -Dsbt.version=1.1.5
+  - SET SCALA_VERSION=2.12.6
+test_script:
+  - sbt "++2.12.6 io/test"
+
+cache:
+  - '%USERPROFILE%\.ivy2\cache'
+  - '%USERPROFILE%\.sbt'
diff --git a/io/src/main/scala/sbt/internal/io/Milli.scala b/io/src/main/scala/sbt/internal/io/Milli.scala
index 47e041e7..22e094f1 100644
--- a/io/src/main/scala/sbt/internal/io/Milli.scala
+++ b/io/src/main/scala/sbt/internal/io/Milli.scala
@@ -17,7 +17,6 @@ import com.sun.jna.{ Native => JNANative }
 import com.sun.jna.Platform
 
 import com.sun.jna.platform.win32.Kernel32
-import com.sun.jna.platform.win32.WinNT.GENERIC_READ
 import com.sun.jna.platform.win32.WinNT.FILE_SHARE_READ
 import com.sun.jna.platform.win32.WinNT.FILE_SHARE_WRITE
 import com.sun.jna.platform.win32.WinNT.FILE_SHARE_DELETE
@@ -30,6 +29,7 @@ import com.sun.jna.platform.win32.WinBase.INVALID_HANDLE_VALUE
 import com.sun.jna.platform.win32.WinBase.FILETIME
 import com.sun.jna.platform.win32.WinError.ERROR_FILE_NOT_FOUND
 import com.sun.jna.platform.win32.WinError.ERROR_PATH_NOT_FOUND
+import com.sun.jna.platform.win32.WinError.ERROR_ACCESS_DENIED
 
 import sbt.io.JavaMilli
 import sbt.internal.io.MacJNA._
@@ -285,6 +285,8 @@ private object WinMilli extends MilliNative[FILETIME] {
       val err = GetLastError()
       if (err == ERROR_FILE_NOT_FOUND || err == ERROR_PATH_NOT_FOUND)
         throw new FileNotFoundException("Not found: " + lpFileName)
+      else if (err == ERROR_ACCESS_DENIED)
+        throw new FileNotFoundException("Access denied: " + lpFileName)
       else
         throw new IOException("CreateFile() failed with error " + GetLastError())
     }
diff --git a/io/src/test/scala/sbt/internal/io/SourceModificationWatchSpec.scala b/io/src/test/scala/sbt/internal/io/SourceModificationWatchSpec.scala
index c61841ed..fe5537ed 100644
--- a/io/src/test/scala/sbt/internal/io/SourceModificationWatchSpec.scala
+++ b/io/src/test/scala/sbt/internal/io/SourceModificationWatchSpec.scala
@@ -360,8 +360,10 @@ abstract class SourceModificationWatchSpec(
       // Longer timeout because there are many file system operations. This can be very expensive
       // especially in the PollingWatchSpec since both the PollingWatchService and the EventMonitor
       // overflow handler are hammering the file system. To minimize the conflicts, we set a long
-      // interval between polls in the PollingWatchService using getServiceWithPollDelay.
-      val deadline = 20.seconds.fromNow
+      // interval between polls in the PollingWatchService using getServiceWithPollDelay. The
+      // timeout was increased from 20.seconds to 40.seconds to address transient failures of
+      // this test on Appveyor windows builds.
+      val deadline = 40.seconds.fromNow
       val monitor =
         defaultMonitor(getServiceWithPollDelay(1.second), parentDir, tc = () => deadline.isOverdue)
       try {