All of the important IE reg settings are under
HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\

Some of the most popular keys are in
HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\AboutURLS

These control the behavior when a site is not found, the blank page, offline pages. The best list of what you can do to IE is actually in Microsoft's new beta AntiSpyWare program (ex-giant software). If you go to their 'Restore Hijacked Interenet Explorer Browser Settings' page, you can see all the hot points. By searching for the current setting (or modifying and searching) you can find all the equivilent registery settings.

Good luck, WCFF