Ridiculous Frame Skip with Every Game!

[zCyra]

Okay, so ever since i re-installed my OS, my computer has this frame-skip when i play any game, or even a high Memory/CPU process in that matter. I usually get 60+ FPS in games like Minecraft, Crossfire, Call of Duty, Etc, but now i getting a 60-0 frame drop for a few seconds, then it goes back up.
My specs are:
Windows 7 Professional 64-bit
Intel i7 1.6GHz (8 Logical CPU's)
4GB DDR3 Memory
ATI Mobility Raedon HD 4570
HDD: 456GB

Its a Dell Studio 1557, (The one with the infamous fan problems.) its super quick, (or used to be)
Please help! I have been dealing with this for months, and its getting to the point where its almost impossible to play games now.
Thanks,
Cyra

P.S. If you want to see what i mean by "Frame Skip," i can record a quick video of minecraft, with fraps (i can record 30fps, full graphics, still frameskips however.)

[Alen]

Stress test your system, check temps and see if anything causes your laptop to start lowering clocks or otherwise reducing performance to cool down