I've never been able to Alt-tab civ3 so i can see desktop, I've always had to use the windows key and then the 'show desktop' icon on the quick launch bar.
Is this how its supposed to be?
Just thought I'd ask this question.

Alt-Tab switches between applications. You can only alt-tab if you have another program running in the windows task list AFAIK, and windows itself doesn't count. Eg: I can't alt-tab to the desktop in Internet explorer either! I also have to use the windows key.

Hmm... I've been able to minimise stuff using Alt-tab before.

Try the suggestion at this link (http://forums.civfanatics.com/showthread.php?p=2067868&postcount=5) ;)