Compaq Armada M700 Mouse Problem, vijay chauhan

Hi to all,
I have Compaq Armada M700. from last one year it was working too good. but since last 2 months, it giving me one typical problem of mouse pointer.
i have point ball mouse between keys and also have USB mouse. before that both were working fine.
but now, when ever i touch the mouse, mouse pointer drags to left cornor of sceen or right cornor of sceen. i am not able to select anything from mouse. and same problem, comes when i use USB mouse.
i dont know its a problem of Mouse Pointer.
or coz, of virus. or
i think i need to repair at compaq service center. but i know they will charge too high,
i will appriciate, if anyone got same problem or could solve my problem please, help me for the same.
if anyone want to contact me, this is my id : [email protected]
thanks, :?: