The tip above was meant for IE4 and IE5, and IE6 *with a different name, though backbitmap should still work:

Running IE6, or using Windows XP, though it comes with IE6, the BackBitmapIE5 value is still the same, but the string value for the explorer toolbar is now called "BackBitmapShell" (same key). Still, BackBitmap works too.
IE7 is not included in this process. The post is over 3 years old. Hopefully you can get it sorted.