Massive FPS lag in all games!

[Keneve]

Some while ago when i played games i could run any game with 60-80 fps and without any problems. Now when i try to play my games,most of them gives me a really annoying unstable 5-20 fps. How can i know what is causing that problem? Please help me guys 🙁
specs: Processor- AMD Athlon(tm) II X3 445 Processor
Video Card- ATI Radeon HD 4600 Series
Memory-4.1 GB

 

[RCguitarist]

What games are you trying to play?

 

[Keneve]

What games are you trying to play?

Most of the games im getting huge fps drops are Garry's Mod,CS:GO, GTA 4 and almost all Valve games.

 

[RCguitarist]

Were you able to run those games fine in the past? Or are you trying those games for the first time? Unless you were able to play those games fine in the past, your pc components are fairly old and your pc just might not be able to handle those games.