Why Is My Computer Running Slow

What programs would work best without slowing down or freezing my computer? I tried using Quickcam (an unregistered version) and Photoshop CS3 at the same time, but it froze on me. Any suggestions? Thanks!

this is a quick and eaey tutorial how to record pc games free all you neede is a great computer and then you can start it becouse if you have a slow computer its will go slow or lag..