Have you considered updating XP to Service Pack 3? And installing IE8?
You might be able to fix IE 6 by running the System File Checker. At the Start menu, choose RUN. Type in: sfc /scannow (there is a blank space after sfc) and press Enter. You might be prompted to put your Windows CD in the CD drive.
If that doesn't work you try to fix problems with IE 6 by installing Windows XP Service Pack 3.