ya, you dont have the drivers. a sure sign of a lack in drivers is SLOW 2D control, like as you said moving windows and scrolling. do this, should fix it...
1 right click my computer
2 properties
3 hardware tab, then click device manager
4 you should see a yellow sign next to your display driver
5 right click it and hit update driver
let it search on the internet. or you can search on the compaq website for the drivers for your machine. better yet, lemme get you a link. (next time build a computer, but anyway here we go)
http://h10025.www1.hp.com/ewfrf/wc/...74&cc=us&os=228
^^ search on this page for some display drivers, or video drivers, its the same thing.
(in the future, try not to make more than one post, we see you the first time, well jsut saying)