--- a/mailnews/imap/test/unit/test_imapHdrChunking.js
+++ b/mailnews/imap/test/unit/test_imapHdrChunking.js
@@ -46,16 +46,18 @@ load("../../../resources/messageGenerato
 
 Components.utils.import("resource://gre/modules/Services.jsm");
 Components.utils.import("resource:///modules/mailServices.js");
 // javascript mime emitter functions
 
 // IMAP pump
 load("../../../resources/IMAPpump.js");
 
+setupIMAPPump();
+
 // Dummy message window so we can say the inbox is open in a window.
 var dummyMsgWindow =
 {
   openFolder : gIMAPInbox,
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIMsgWindow,
                                          Ci.nsISupportsWeakReference])
 };
 
@@ -151,23 +153,21 @@ function testHdrsDownloaded() {
 // Cleanup
 function endTest() {
   teardownIMAPPump();
 }
 
 function run_test()
 {
   // XXX Disable on windows for now as it is failing there.
-//  if ("@mozilla.org/windows-registry-key;1" in Cc) {
-//    dump("Disabled on windows due to permanent failures\n");
-    // disable everywhere
+  if ("@mozilla.org/windows-registry-key;1" in Cc) {
+    dump("Disabled on windows due to permanent failures\n");
+    endTest();
     return;
-//  }
-
-  setupIMAPPump();
+  }
 
   // We need to register the dummyMsgWindow so that we'll think the
   // Inbox is open in a folder and fetch headers in chunks.
   MailServices.mailSession.AddMsgWindow(dummyMsgWindow);
   MailServices.mfn.addListener(mfnListener, MailServices.mfn.msgAdded);
 
   // Set chunk size to 3, so we'll have to chain 4 requests to get
   // 10 headers.