hottiecakes

Hi... I'm a newbie, and I have upgraded to windows XP, ever since I did that, a window pops up telling me something about LSA shell and then another window pops up telling me lsass.exe failed or something of that sort and will shut down in 60 seconds!!!!!!! I've reformatted several times thinking it might fix it, but no luck! I'm getting very frustrated and don't know how to repair it. Also my IE keeps messing up and won't let me type in the browser and search for anything..... if anyone can help me I would greatly appreciate it. Thanks!