Computer Skipping Every Few Seconds

i recently just got this problem, umm the first thing i started to notice was my startup becoming extreamly slow, at that point i thought there was a problem, so when i finally got through the startup, i move my mouse around and like every few seconds it would skip, so basically you move it and then 3 seconds later it skips so you basically see a lag spike or something. it continues for awhile and then stops like maybe 10 min later. but then starts again everytime i open a program ex: counter strike, Azureus, microsoft word.