Slow moving windows after Win XP installed?

Have an old Lattitude, and I recently bought a new hard disk drive since the previous had crashed.

After formatting the new disk and reinstallning Windows XP initially all looked ok.

But when I click to move a window it follws very slowly and lags the move of my pointer. 

I would appreciate any tips on what might be the problem and what can be done to solve it!

Regards, Cris