Question windows explorer, photo viewer, VLC, etc.. stuck at random times

[whiteknights]

I'm facing a problem since a few days my pc run normally and out of no where when i try to open "My computer", "Recycle bin", any browser tab it gets stuck for a while and show "not responding. although CPU load & Ram usage are low, all my components Temperature are perfectly normal, there is more than 10% free space in my hard drive, and games runs normally.

things i'v tried:

1- scanned my pc with anti-virus and anti-maleware
2- i did a CHKSDK for bad sectors
3- re-installed my GPU driver with a new one
4-used CCleaner to remove pc trashes
5- defragged my drive

My PC specs: Windows 7 Ultimate - 8G Ram 4 x 2 - intel i5-3470 - Nividia GTX 1060 3GB - WD 1TB Blue - Gigabyte H61m-S2p - HEXA+ 500W PSU.

any idea what could the problem be?

 

[whiteknights]

Update: so after monitoring Hard Disk throgh Resource monitor i've noticed that when this problem happens disk "Highest active time" gets stuck at 100% , and Disk I/O decreases from megabytes to kilobytes.. i dunno why this is happening, why my disk highest activity stuck at 100?, even though i removed lots of programs and files even my antivirus.