Hi, Jan.
No other quick'n'easy suggestion. :>(
You may need to do the "in-place upgrade". Here's a copy'n'paste from my
response just yesterday to another poster ("Phil") with a similar problem:
Clean install is best - unless you have applications that would take time
and effort to reinstall and/or data that you haven't backed up. In that
case, you could do an "in-place upgrade"; this would take as long as a clean
install of WinXP itself, but would preserve those apps and data.
For full instructions, see:
How to Perform an In-Place Upgrade (Reinstallation) of Windows XP
http://support.microsoft.com/default.aspx?scid=KB;en-us;q315341
After either a clean install or an in-place upgrade, make sure your firewall
and antivirus software are working, then visit Windows Update as soon as you
get back online to be sure you have all the fixes, like the one from last
July that protects you from the Blaster worm.
All this reinstall, plus download and install updates, probably will take
half a day, Jan. So I hope someone else can come up with a less traumatic
solution.
Normally, I'd say to search for solutions to the "page fault" error message.
But, since it occurs when you try to enter RegEdit, the real problem may be
hidden within WinXP itself somewhere. That's why I suggested to try SFC
first. Since that didn't work, you probably will get back to work soonest
by skipping the search for the cause and just bypass the roadblock by
reinstalling WinXP.
Let us know how things work out for you. In a newsgroup, we all learn from
each other.
RC