Index: src/filesystem/TempFile.php
===================================================================
--- src/filesystem/TempFile.php
+++ src/filesystem/TempFile.php
@@ -19,6 +19,7 @@
   private $dir;
   private $file;
   private $preserve;
+  private $ignoreRemovalFailure;
   private $destroyed = false;
 
 /* -(  Creating a Temporary File  )------------------------------------------ */
@@ -64,6 +65,21 @@
     return $this;
   }
 
+  
+  /**
+   * Normally, failure to remove the file is considered to be an exception, which
+   * will fail the process with an error exit code.  However, Windows loves to hold
+   * file locks, preventing the deletion of files.
+   *
+   * @param bool True to ignore failure removing the file.
+   * @return this
+   * @task config
+   */
+  public function setIgnoreRemovalFailure($ignore) {
+    $this->ignoreRemovalFailure = $ignore;
+    return $this;
+  }
+
 
 /* -(  Internals  )---------------------------------------------------------- */
 
@@ -95,14 +111,20 @@
       return;
     }
 
-    Filesystem::remove($this->dir);
+    try {
+      @Filesystem::remove($this->dir);
 
-    // NOTE: tempnam() doesn't guarantee it will return a file inside the
-    // directory you passed to the function, so we make sure to nuke the file
-    // explicitly.
-
-    Filesystem::remove($this->file);
+      // NOTE: tempnam() doesn't guarantee it will return a file inside the
+      // directory you passed to the function, so we make sure to nuke the file
+      // explicitly.
 
+      @Filesystem::remove($this->file);
+    } catch (Exception $ex) {
+      if (!$this->ignoreRemovalFailure) {
+        throw $ex;
+      }
+    }
+    
     $this->file = null;
     $this->dir = null;
     $this->destroyed = true;
Index: src/future/exec/ExecFuture.php
===================================================================
--- src/future/exec/ExecFuture.php
+++ src/future/exec/ExecFuture.php
@@ -706,6 +706,9 @@
       if ($this->useWindowsFileStreams) {
         $this->windowsStdoutTempFile = new TempFile();
         $this->windowsStderrTempFile = new TempFile();
+        
+        $this->windowsStdoutTempFile->setIgnoreRemovalFailure(true);
+        $this->windowsStderrTempFile->setIgnoreRemovalFailure(true);
 
         $spec = array(
           0 => self::$descriptorSpec[0],  // stdin