Question PC gets unresponsive after inactivity period

[rscheetah30]

After a few minutes of inactivity my pc gets unresponsive for a few seconds, there's a bit of lag and then it goes back to normal. I don't remember installing any new software recently and haven't changed my hardware.

Here are my pc specs:

Windows 7 Ultimate 64

CPU: i5 3570K
RAM: 6GB DDR3
MB: Bluecase BMBH61-S
GPU: nVidia Quadro 2000D 1GB DDR5
PSU: Hoopson 500W

Thx in advance!

 

[rgd1101]

power saving mode?
auto virus scan?

 

[rscheetah30]

power saving mode?
auto virus scan?

I disabled hybernation and for now it seems it's gone back to normal.