Click “Start,” and then click “Control Panel.”
Click “Add or Remove Programs.”
Check “Show Updates” at the top of the dialog box.
Scroll down the list to “Windows XP – Software Updates,” select “Internet Explorer 7,” and then click "Change/Remove."
Removing IE7 rolls your computer back to IE6
If the above allows IE 6 to run properly and you want to reinstall IE7, read the recommended actions to take before installing in the link below.http://www.ie-vista.com/known_issues.html
If IE is the only browser you have installed on your computer, I would suggest strongly that you install Firefox.