Computer lagging with no reason.

[Ikak]

It's a nightmare! After a few minutes of using the computer (20 minutes in avarage) my computer starts lagging with no clear reason. About every second there's about a 0.3 sec lag, the computer is lagging, not internet lag.
These are my PC specs (OS windows 7 x64 is in Hebrew so sorry for that):

http://imagizer.imageshack.us/a/img673/8765/fy09g6.jpg

Graphic card:

http://imagizer.imageshack.us/a/img537/3690/1rbT7N.jpg

Processes:

http://imagizer.imageshack.us/a/img537/645/pCP248.jpg

Performences:

http://imageshack.com/a/img673/7956/EmeDnT.jpg

I already cleaned pc with CCleaner and scanned with Malwarebytes Anti-Malware and defragged hard drive and updated Graphic card's driver and nothing seems to help. Formatting is a bit of a problem but possible.

 

[Aykiddo]

Type msconfig and remove the unneeded starting programs. Also boot into safe mode and see if you experience the same lag.

 

[Ikak]

Type msconfig and remove the unneeded starting programs. Also boot into safe mode and see if you experience the same lag.

Done that, Still lagging.