PC Hanging a lot

[samargamer]

My PC which runs Windows 8.1 hangs a lot. Everything takes a lot of time. When I press the 'Start' button, the window will open after a lot of time. If I open 'Windows Explorer', 'My Computer' would open after a very long time. Even when switching it on, either it would take 20 minutes, or it won't switch on at all.
I used to have the same problem with Windows 7 too, so I got my PC formatted and installed Windows 7 Ultimate. The problem sprang up again. So I went out and bought a new hard drive and installed win8.1 on it (the problem was gone till recently) . But the problem has now sprung up in 8.1 also. I cleaned my PC with CCLEANER and ran a full scan with AVAST! but I came up empty. I don't have any idea what causes it. My PC starts hanging all of a sudden, and then after some time, ranging from a day to 20 minutes, it would start working normally again. Please help.





Edit: I also ran the SSID utility in windows 8.1 and even it shows no errors.

Rarely I get an error during boot saying: Media test failure.
And then nothing happens. But that too gets fixed by itself after some time.

 

[samargamer]

Anyone? :/

 

[samargamer]

As I had mentioned earlier, it fixes sometimes by itself for some time. That's what happened today. It started working normally however in the middle of a browsing session, my PC froze and it shut down.


Now when I try to turn the PC on, I hear two beeps and then I am stuck on a screen that says something like: The following device is covered under the following patents......


My PC is falling apart.

 

[samargamer]

Okay, now it said at startup: "Boot failure" in white text on a black background.
After restarting many many times, it has switched on but it still is hanging, even at the Windows 8.1 loading screen.






PXE-E52 : No boot filename received

PSE-MOF : Exiting PXE ROM

 

[samargamer]

Boot failure error is gone but now I am stuck at the Windows 8.1 loading screen, with the blue window.


EDIT: Since the PC was stuck there, I did a manual restart and now I am stuck yet again at a screen-


White text on black background. Says "Exiting PXE ROM" at the end.





Edit: Now the Windows 8.1 starting screen, the one with the blue windows logo shows up, it remains there for a long time, then a blues sad smiley appears on the screen. Then the PC restarts. While booting after the shutting down, I am stuck at the above black screen with white text.