I don't know if this works in xp or if there's any risk involved (but b/up data in case):
Look in your c:\windows\inf folder and see if you find any files named oemxx.inf which have a length of 0 (zero), where the xx can be any number.
There could be potentially many thousands. If you do, you need to erase these.
Here's a MS article: click here;en-us;281967 : Computer Stops Responding (Hangs) During Setup, Installing Updates, or Adding New Hardware
Now go to Start/Find, and type wininit.ini
When found, highlight the file and hit 'delete'
Warning: leave Wininit.exe, Wininit.bak, and Win.ini alone
Go to C:\Windows\Temp, and empty the folder completely.
Go to Microsoft Download Center ( click here? ), and select the version of IE you'd like to download.
Now shut down as many running programs as possible, especially your antivirus, and try downloading and installing IE again.