Just thought that I would document a situation that seems to occur.
Last night, I got the bright idea to do a repair install of XP Home, for no particular reason. I had a CD (not slipstreamed, acquired with a PC I bought last year) and I thought I'd try it out, rather than using my slipstreamed copy.
In any case, something went wrong and when I finally was able to get my desktop back...I found that IE6 was reflected as my browser and I could not obtain any support/downloads from the MS website. IE seemed to be working OK for other sites, but not at Microsoft.
Turns out that the repair install process had borked the uninstall of IE8, with the result that the IE7 engine was running behind the IE6 browser which appeared to be properly installed. Since several functions depend on the proper functioning of IE, I found that I could not access Help & Support, download anything from the MS website, etc.
The suggested fixes for this are a routine deletion of IE7 (take a look via Google for topic) or a clean install. The routine suggested to remove IE7 wasn't even possible, since I did not have one of the key files suggested as the .exe, it was not in my IE7 folder.
Ultimately, I decided to reverse the reasoning of many...rather than remove IE7 (which wasn't possible), I would install IE8 from the files I maintain (I keep copies of every major program I install, including SPs and browser changes).
Installing IE8 worked, subsequently this system is back online and I am sat with my efforts in this situation
Hopefully, this may help someone who finds herself/himself in a similar situation where the oft-suggested fix just cannot be done.