Thanks for all the replies & advice...I found an article Cat linked to in a previous post about the 320.18 drivers, which detailed how to clean the system & install previous drivers. I just hope it's not a sign that my GPU is dying

I'm off to try a few games & see if it's any better...
Update
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I'm happy to report that installing the older drivers seems to have fixed the problem. In the article I read about this issue, it stated that some people were reporting damaged GPUs as a result of the 320.18 drivers...so much for being Windows certified! I'm relieved my system is okay now. Thanks for all the help, once again
