laptop is breaking down

[JustAnotherNewbie]

I'm the owner of a Lenovo G480. Nvidia GT635M, 6gb of ram, intel i5. It used to run very quickly when it was fairly new up to a few months old, even being able to play crysis 3 on medium-high. then it started slowing down noticeably, to the point that even dota 2 can only get ~30fps at peak, on lowest settings.

What could be causing this, and is there any way bar factory resetting to at least let me play dota 2 decently?

 

[Phillip Corcoran]

Have you defragged the HDD recently?

 

[JustAnotherNewbie]

Have you defragged the HDD recently?

I've defragged it pretty often, usually once a month, sometimes more, if my weekly scans show some undesirable results. Only thing abnormal is the slow speeds, and the high temps near where the fans are.