The only thread I can find between the two may be that you are having network communication issues. How good is your speed to the internet (there are lots of tests around the web for that)? Does your firewall or router block certain sites or ports? Can you get a game playing in online multiplayer without much problem? (You can try the Unreal Tournament 2004 demo; it has several good maps for testing purposes, or any other heavy duty games that require fast communication online).
Daemon tools has had a history of issues with Vista, and may have some more with Windows 7, so you may want to be careful with it. If all you want to do is mount .ISO files as drives, there are some leaner and less intrusive tools. Daemon Tools do provide some...