Serious problems with lag with both G5 and G500 logitech mouses.

Hi there. I've read some previous posts of this problem, but there was wireless mouses included.

Anyhow... I'm swedish but the stuff should be the same. I've had this problem since I changed my graphics card, now I think you'd say "Update Drivers" .I can tell you now already that I've already done that.. This lag I'm talking about is constantly happening when I'm playing ANY games, some exceptions would be older gams. Anyhow.. here's my computer:

Windows XP professional SP3
AMD Phenom 9750 Quad Core 2,41 GHz this piece is about 1 year old, give or take..
2 GB RAM these pieces are almost 3 years old
XFX Geforce 9800 GTX+ 512 MB GDDR3 Black Edition. aprox. 6 months old.


Right now, I'm using the G500 mouse, but since a while back I've been using the G5. The most weird thing about this is that my G5 mouse worked perfectly before I changed my graphics card and I also changed my Operating System. I think I had another XP pro SP3. Not sure though. I've been thinking of reasons for this incredibly weird lag from the mouse, Reason #1: not enough RAM, Reason #2: Something is very screwed with my OP system, Reason #3: My processor got damaged when I did the changes with my computer. Reason #4: Some other part of my computer got damaged. If someone could tell me if I'm wrong and come up with some awesome sollution, I would be forever grateful. Thank you in advance.

(didn't find a fitting place to post this in the categorys, but CPU and Components would match pretty good.)