Random freeze on PC

[GamersProblem]

So as stated above whenever i play League of Legends my computer just randomly freeze! I have an issue on my Hard Drive and it's very old, i open the task manager and click on the performance tab and guess what my Hard Drive is on 100% usage, and i don't know why? sometimes it tend to go down a little bit but after an hour it's on maximum usage again, and after that my computer just gonna go randomly freeze but still "i hear the background processing or the sound still ongoing" my monitor do pop like there's "No Signal" and after that it's gonna go back to the game but still do hangs and pop "No Signal" again and after that it's gonna automatically restart my PC for me.

My GPU temperature is quite normal, i can only assume that maybe it's my Hard Drive or my Monitor? and also i almost forgot. That whenever i play videos on Facebook that's the time that my PC will surely freeze, and pop the "No Signal" on my monitor again. I did try different solutions like (disabling the superfetch, etc..) there are so many things that i have done but none of them work, i think it's really an Hardware issue's.

Specs:
CPU:I7-4790
RAM: 8GB HyperX (2x4GB)
GPU: Sapphire Radeon R9 270
Motherboard: Asus H97M-E
PowerSupply: FSP 700W
Hard Drive: Western Digital 320GB (OS Installed)
Hard Drive: Seagate 500GB

Here are the screenshots:

Update:
07/05/2015 -- I reformat my PC again to Windows 8.1 64-bit, and change the Operating System to my Hard Drive that doesn't have the (100% issue thingy which is the 500gb Seagate) it didn't go back to the 100% usage which i have stated. But the problem still do occur whenever i watch videos (on Facebook, and now on Youtube!) my computer goes "No Signal" again and restarted itself automatically. So i could say that this is not a Hard Drive issue, but rather a GPU? Please don't! I don't have enough budget anymore to buy another GPU if this is the problem.

 

[avenseth12]

What settings are you trying to play the game on? What drivers do you have installed? Are they the most recent? Sometimes AMD drivers don't play with games, you may have to downgrade to an older version.

 

[GamersProblem]

What settings are you trying to play the game on? What drivers do you have installed? Are they the most recent? Sometimes AMD drivers don't play with games, you may have to downgrade to an older version.

I am on the Omega Driver AMD.

Is that true? Should i downgrade? because as you can see i am on the Catalyst Software Suite, What's the difference between that Omega Driver they have released and the Latest Beta Driver which they say version (15.6)? I only download the Omega, i didn't download the Latest Beta? I though it's the same which is Omega is the latest? I'm confused lol.

http://support.amd.com/en-us/download/desktop?os=Windows+8.1+-+64

 

[Darkbreeze]

If you know you have an issue with your hard drive, then that needs to get resolved before anything else get's looked at. The best, cleanest windows and drivers installation are worthless if there are drive related issues, since all that information needs to be accessed in order for things to work correctly. I'd resolve the drive issue, likely by replacing the drive and doing a clean install of windows, and then see where you're at with the problems you're having now. I suspect it may resolve the issues without further diagnosis needed.