Sound and Mouse/Keyboard Stuttering

[Citrus]

I have an issue with my Windows 7 PC randomly stuttering. If I play a Youtube video or MP3 the sound will randomly stutter for a second and then go back to normal. If I'm playing a video game the sound will stutter along with the mouse and keyboard. It seems to be happening randomly and I am not able to figure out the culprit. When I check my system resources there is nothing straining the system. Windows is fully patched and I have updated my graphics and sound drivers. I had a secondary hard-drive that was failing which I thought might be the issue but even after replacing it with a new one the problem remains.
Is it a hardware issue or a software issue? How can I figure out what's causing it?

My system details:
Windows 7 Ultimate 64 Bit
8 GB of RAM
200 GB of free space on the OS volume
Nvidia Geforce 9800GT

 

[fireberd]

Download and run the free Latency Mon. It may help you find what is causing it.

As the sound, mouse and keyboard are doing it at the same time says its a system problem and not specifically a sound problem.

Resplendence Software - LatencyMon: suitability checker for real-time audio and other tasks

 

[Citrus]

When you say "system problem" do you mean with the OS or with the hardware?

 

[fireberd]

Could be either, but I more suspect software.

Run the Respledence Latency Mon and see what it tells you.