Control Panel won't open

Every time I try to open this, it refreshes the page. Desktop icons
disappear, leaving only the background wallpaper and then reappear as if I
hadn't tried anything. Has anyone heard of such an event? Event Viewer has no
errors, I tried to reinstall the rundll.exe from CD as mentioned in a
Microsoft online help doc, did a cfs /scannow, nothing happened, used
Ashampoo Winoptimizer 2002 to clean the registry, all of which have not
solved the issue.

Any further help greatly appreciated.
.