You should check your security settings and make sure that your account is
authorized to do the install. Win7 will block you but not tell you
mine had the same thing. I lowered the security settings and now its an error message.. E_ADEPT_EXPIRED or something like that.
Im so bummed out with ADOBE right now.. what a fail. Theyve always screwed up in my books.
You may find v 1.7.2 works better.
There are a few known problems introduced with ADE2.0; that one doesn't look familiar but probably worth a try.
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172