First some background: I have a Dell Inspiron 15R M050, it is still under the Dell limited warranty and the Best Buy Extended warranty. I am currently dual booting Debian Squeeze and Windows 7, the only reason I go into Windows is to play video games specifically steam games.

Issue: When I play my games in Windows I am capable of playing for anywhere from 5 minutes to 2 hours before I suffer a hard-lock. I cannot alt-tab, ctrl-alt-delete, ctrl-shift-escape do anything for 2-3 minutes. After this hard-lock period everything runs fine, I can continue the game for probably another hour at least before I suffer another lock.

Games: Borderlands, Splinter Cell: Chaos Theory, Starcraft 2, Garrys Mod

What I have tried: Running the diagnostic suite in the dell bios, restoring the OEM Windows recovery partition on the HD, fresh installing Windows 7 Professional, updating BIOS, Calling tech support and having them run a software Hardware Diagnostics suite.

The question: I think from the research that I have performed that it might be a lack of thermal paste on the CPU, would I be able to go to Best Buy and have them do a hardware diagnostic from the hardware level then have them be able to tell Dell that there is a hardware issue? Or would there be a different problem?