Windows 7: Lagging and Sound Distortion

Hi! This problem began happening a couple weeks ago. Every now and then, at random intervals, whatever I'm doing, my computer will begin having extreme lag. The music I'm listening to will distort, any games I'm playing will drop to 10 or lower FPS, my ping in the game spikes to 2000+, even though the internet is fine at the time. This happens when I am using offline applications as well, such as reading pdf files, or typing word documents. The problem seems to intensify as I use my computer for longer periods of times. There are no viruses on this computer, I've checked using multiple virus scans. Is this possibly a hardware problem?

Thanks for any help.

Yes, possibly hardware.

The standard test for RAM is memtest86+. Run it for 6 or 8 passes, which might take overnight.

For hard drives, use the drive manufacturer's testing tool, downloadable from the manufacturer's web site in the support area.

Get memtest86+ here and burn it to a disk and boot from it.

Memtest86+ - Advanced Memory Diagnostic Tool

Have you taken a look at processes or RAM usage in Task Manager or Resource Monitor during the times that the PC is lagging??

Some info about your hardware might help--CPU, hard drives, and RAM at least.

Processor: Intel(R) Core(TM) i7-2630QM CPU @ 2.00GHz (8 CPUs)
Memory: 8192 RAM (Believe the brand is Crucial)
Hard Drive: Hitachi HTS547564A9E384 (5400 RPM HDD)

I will give MemTest a try, as I was planning on doing so.
I have not looked at task manager during these lag phases due to the fact that happen so quick and they last for such a short time, the longest was maybe 10 seconds, and the shortest is less than 1 second.

I noticed my CPU usage spiking during these times.