hi Thomas,
This link here is a Microsoft Knowledge base article on your problem you were getting when trying to use IE with Windows Update.
You may receive an "Error 0x80072EE2," "Error 0x80072EE7," "Error 0x80072EFD," "Error 0x80072F76," or "Error 0x80072F78" error message when you try to use the Windows Update Web site or the Microsoft Update Web site
In regards to using regedit and messing your computer up - use Mozilla Firefox and go here
https://addons.mozilla.org/firefox/1419/
Install IE Tabs, and once that's installed, right click on this link here
Microsoft Windows Update and select
Open in IE Tab
This should get you into windows update - reinstall IE7 and then follow the knowledgebase article to resolve your initial issues.
unless you know 100% what you're doing - never go into the registry - it has the power to completel render the computer useless
unfortunately you
need the windows cd before you can reinstall windows - there is no way around this.