My Open Windows Freeze Periodically, Help?

Every now and then my open windows (such as Google Chrome, a Game I may be running, Skype, Etc.) will freeze (all at the same time, and note only the windows freeze NOT the computer) at random every few minutes or so for up to 30 seconds. This problem has been persisting for the past month or so and I have yet to find a cause for it. My anti-virus (Microsoft Security Essentials) shows my computer virus clean (which is true) and I have not downloaded any programs that would cause such behavior. What I believe may be the problem is the driver for some part of my computer being out of date, or some other problem with it (considering this problem started happening around the time I updated my HD4850/CCC to 11.5a.) I’m currently running Windows 7 64 bit, 4gbs of ram, HD4850 video card, and a AMD Phenom II X4 945 Processor (~3.0 ghz). Any help would be appreciated, thank you.