I don't actually use IE on a day to day basis so, when I decided to upgrade from 6 to 7 some time ago, I think I used the Windows Update site (but not Automatic Update because I have that turned off).
It's been too long for me to remember exactly what happened but I know I didn't have any problems with the upgrade. I keep an eye on various sites and newsletters and am thinking about moving to IE 8 in the not too distant future since most of the problems with it appear to be resolved. I will upgrade only because of the security enhancements 8 is supposed to have, not because I intend to use it.
If you don't feel brave enough to go direct to IE 8, I found a link for IE 7 for XP SP2 or 3. If your version doesn't have the Service Packs you will need to check the other links on the page;
http://www.microsoft.com/downloads/d...0-081805b2f90b
.