SFC.EXE /SCANNOW may help:
http://www.bleepingcomputer.com/forums/topic43051.html

Repair installation of XP - leaves data and programs intact:
http://www.michaelstevenstech.com/XPrepairinstall.htm

- John

"Dave Cullen" wrote:

> After installing Microsoft Visual Studio.NET on my computer the standard
> Windows dialog box component is not displaying correctly. The text
> inside and on buttons does not display. Part of the installation
> included a "Windows Component Update", which probably broke something.
>
> Is there a way to overwrite the standard Windows control files without
> uninstalling what I just did or reinstalling Xp?
>