System repair not working

[hdawnn18]

So... Earlier today my laptop was running very slow. I opened it and tried to go onto the internet, but nothing was opening. Instead, after about ten minutes my wallpaper and taskbar disappeared. The cursor turned into the blue circle and the computer froze.

After that, I decided to manually shut it off and turn it back on. Ever since then, my laptop gives me the choice to run systems repair or to boot normally. Whenever I boot normally, a blue screen flashes and restarts, and when I try to run system repair, the screen goes black for several minutes and goes into the blue background for the login screen. The cursor shows and I can move it around, but I can't do anything else.

How do I fix this?

 

[TrainableMan]

If your computer computer "suddenly" slowed down then a virus is a good possibility. Use another computer and download TDSSKilller & RKill to a USB flash drive.

Can you boot into safe mode? As your computer is booting up hit F8. Once in safe mode, Run TDSSKiller, then RKill, and then a complete virus scan.

... or it could be a hardware problem. ...
Insert a W7 DVD and boot up to that. Choose a DOS Command Prompt, type "C:"<enter> and then run "chkdsk /r"<enter>. Does it show a hard drive problem?

 

[hdawnn18]

I can't boot into anything. It shows a flash of bluescreen and then restarts.

I also had to download a new w7 dvd (because I don't know what happened to mine), anyway, when I try to boot it, nothing happens. Even if I set it up to boot the dvd drive first.

I've also tried to wipe the hard drive using DBAN, and nothing has changed. The program seemed to run and finish, then when I boot the computer again, I had the exact same problem.

 

[TrainableMan]

when I try to boot it, nothing happens. Even if I set it up to boot the dvd drive first.

Then it most likely wasn't created properly. If the DVD just contains a single file then it is not correct.