You cannot uninstall IE, Microsoft integrated the program into windows so its a very critical part of the operating system. When you repair windows you go back what the CD has, in your case thats SP1, i hope, you shouldnt have to manually roll anything back on your own. Use
this link to repair the operating system. Remember to COMPLETELY disconnect from the internet when you're doing this. After the repair completes turn on your anti-virus software and your firewall and THEN reconnect to the internet to update/activate windows. Thats that for repairing windows. To update your windows you need to go to windows update in IE and, in case you dont have it, get the latest version of windows update software. After that installs then get all your updates. And thats that for all that.