diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 1107c6b574cf..5fc6de8ab8fe 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -170,10 +170,6 @@ let gInitialPages = [
 
 XPCOMUtils.defineLazyGetter(this, "Win7Features", function () {
 #ifdef XP_WIN
-  // Bug 666808 - AeroPeek support for e10s
-  if (!gMultiProcessBrowser)
-    return null;
-
   const WINTASKBAR_CONTRACTID = "@mozilla.org/windows-taskbar;1";
   if (WINTASKBAR_CONTRACTID in Cc &&
       Cc[WINTASKBAR_CONTRACTID].getService(Ci.nsIWinTaskbar).available) {
@@ -1139,8 +1135,11 @@ var gBrowserInit = {
     gBrowser.mPanelContainer.addEventListener("PreviewBrowserTheme", LightWeightThemeWebInstaller, false, true);
     gBrowser.mPanelContainer.addEventListener("ResetBrowserThemePreview", LightWeightThemeWebInstaller, false, true);
 
-    if (Win7Features)
-      Win7Features.onOpenWindow();
+    // Bug 666808 - AeroPeek support for e10s
+    if (!gMultiProcessBrowser) {
+      if (Win7Features)
+        Win7Features.onOpenWindow();
+    }
 
    // called when we go into full screen, even if initiated by a web page script
     window.addEventListener("fullscreen", onFullScreen, true);