I've been using Mozilla's Firefox for a few months now and love it. I was having lots of issues with IE7 as well, but since the switchover, I think I've only had 1 crash. The nice thing, is that if your browser closes unexpectedly, when you restart it will offer to reload all the pages you had open when it shut down.
On my MacBook Pro, I'm using FF3 on the Mac side and FF3 and IE8 on the PC side. I can honestly say I really, really dig IE8. It has been stable, quick, and the GUI is functional minimalist.
Im going to wait awhile to move to IE8. I have been reading with PC World and a few other tech sites. Many websites havent updated their code for IE8 yet. So you wont get see their site. Or you will see scrambled versioons of them.
Also it just came out of beta. That gives me caution from past experiance. IE7 is working good for me. I have enough security not to worry.
If you are running a latter version of XP. IE7 may be built into the OS. It is a different proccess to delete 7, in that case. If 7 is in your add remove programs. You might delete it. Then go to microsoft IE site and download the full version of 7 or 8.
If that dont help, your system files are corupt. Since XP came out, IE is not completely independent of the OS.
I have IE on my computers, but hardly ever use it. There are some Microsoft sites that won't work with Firefox or Google Chrome, and that is the only reason it is on anything I own.