Sometimes you may want to reinstall IE 6.0 from your XP CD. This can also be tried if sfc /scannow has failed to fix it.
To do so follow these steps:
1.Insert the Windows XP CD in your CD drive.
2.Open Start / Run and type:
rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 c:\windows\inf\ie.inf
(in one long line. Just copy/paste the above entry)
4.Close IE and reopen it again.