Windows Explorer and Internet Explorer trashed after SpyHunter cle

Sometime ago, I tried to clean up my spyware problems by installing and
running a program called SpyHunter. I clean all recommended intruders and
since have not been able to run any programs associated with explorer,
including Windows Explorer, Internet Explorer, My Computer, My Network
Places, etc. When I attempt to run any of these the screen flashes, the
taskbar vanishes for a few seconds, and nothing launches. I tried rolling
back the changes from SpyHunter but that did not help. I realize too late
that I should have restored to a previous restore point.

I have tried reinstalling Internet Explorer, Upgrade Install of XP, and
Upgrade to SP2 which gives me the popular STOP C0000135 {Unable to locate
component}. Thanks to this forum, I have recovered form that. The reinstall
of Internet Explorer completed but did not help. I used a reg mod to trick
the reinstall per a MS article. The Upgrade install gets to a point where it
says that I have not completely installed and will not continue.

Does anybody know how I can force repair install of XP or repair explorer?

Thanks,
Christian