Your graphics card, is it very memory intensive? Say 128MB or
anything more?
This could be a cause for the lag, and if you don't have enough
memory, it will cause the above symptoms.
As for the playing games part, are your games old? If yes, try
using Microsoft Compatibility Program. (I'm assuming you are using
XP).
Go to Start, All Programs, Accessories, Program Compatibility
Wizard. Follow the instructions.
If your games aren't old, check the system requirements for the
game. Some games require high resolution, and if your graphics card
doesn't support it, it will load, but images will be distorted.
