Though I posted this in the newbie forum.. I thought that i'd crosspost it here...
It may repeat some of what others have said, but it might be worth going through the motions again - it sounds as though you've got a DLL hijacker which causes IE to react the way that it does... I had one of those and removed one of the problems by checking the 'System startup' function in the advanced tools on Spybot... there's usually a loading of some DLL related to internet explorer in there - it is probably what's causing your problem.
Also, check for viruses using the online scanner - it's worth it as some installed ones (Norton is terrible) can be disabled by viruses.
2) I've seen IE getting redirected to various webpages at startup, and it's caused by a number of reasons including:
Kazaa (It's the mother of all spyware
A dodgy Internet Explorer DLL (caused by one of the above)
A dodgy hosts file (caused by one of the above)
Here's what you can do to solve those problems:
Go to Trendmicro's website and use their free virus checker (http://housecall.trendmicro.com) and use this to scan for viruses, fixing/deleting any files that cause a problem
I recommend using 'Spybot Search and Destroy' (http://www.safer-networking.org) - download this program (it's free!), install it and run it, removing all of the entries that pop up there. Also note: v1.3 is newly out - it's better and it's WELL worth downloading.
*** Warning - Kazaa ***
If you have kazaa installed, running and removing all of the spyware that Spybot finds will cause Kazaa not to work again. If Kazaa is an essential for you, you may have to leave all the spyware in place... or try a different P2P program (or Kazaa Lite Resurrection.. but sssh, I didn't say that)
*** End of warning ***
Spybot should sort out this problem for you, but if not there is a file in the Windows directory (C:\Windows) called 'Hosts' ... usually this should only have a few entries (such as 127.0.0.1 localhost) .. if there are any more, delete them.
In addition to the above, I would also recommend that you delete all of your cookies, and all of your temporary internet files by using the 'Internet Options' in the 'Tools' Menu. Also be wary of setting your security level below medium otherwise you could get into trouble.
That's about all that I can recommend - but I've fixed about 20 friends computers this way (well, I did other things too.. but I don't have the time to go through every solution)
I hope this helps...