...and installing a beta program certainly isn't for "Newbies". The general uninstall instructions for IE8 are to use the Control Panel/Add-Remove Programs section to uninstall. Have you tried that?
Have you tried the beta forums for IE8? I'm sure they will appreciate your input and may have a solution to your issue.
Internet Explorer 8 Help & Support Site
Internet Explorer Beta Newsgroup
Hope this helps.
A couple of days ago, I downloaded IE8. Finding myself unable to access some sites with IE8, I tried to redownload IE7 only to be told that a newer version of IE is already installed and the IE7 installation would not continue. IE 8 has removed IE7 so system restore is no help. Any ideas?