Computer makes high pitch whining noise.?

[DylanS]

ive just started to notice my computer makes a highpitch whining noise and on my mouse the little scroll thing in the middle or wheel what ever you call it when ever i move that up and down the whining stops any suggestions?
nope i didnt make any changes its not like so bad where i have to return it but it does get annoying and i didnt mod or anything like that

 

[Tassular]

if it never stops as in one rly long signal it means something is wrong with the compter. i got that problem when i was over clocking my grafik card. u istalled or made any changes latley?