Windows 7 Not Starting

Hello, before I start I would like to let you know that I know about some things with computers but I know almost nothing about harddrive and boot up problems. In the past week or so I have been getting an I/O device error whenever I tried installing a game or program(not sure if relevant to the problem). Today I had to hard shutdown my computer many times because it kept freezing. I updated iTunes and had to restart to apply changes, when it restarted it ran a disc check before windows started, I walked away and when I came back it was at a screen that said Windows failed to start, I have tried both options many times either Launch Startup Fixer or Start Windows normally. Both option lead me to a black screen with my cursor which is about three times its normal size. I have a Windows 7 reinstallation disc but I have no idea how to use it without Windows not working. Does anyone have an advice on what I should do.

 

Hi Shagen. Welcome to Computer Help Forums.
If the Windows7 Disc is not a pirated copy then put the Disc in and attempt a start up repair. 
 
If the Disc is not genuine then you wont have this option on the Disc.
 
If your not sure how to do this then wait for instructions.

 

Ok, my friend gave me the disc awhile ago, it came with a laptop that he custom built. I selected the Start up repair option with the disc in and after about 20 minutes the Startup Repair started check for problems. It hasnt found any problems and has been running for about 45 minutes

 

This sounds like a party disc that anyone uses. It is plainly not working with your computer.
If it is the right legit disc it will tell you in 1 minute whether it was successful or not.
Not 45 mins.
I suggest you get the right disc and try again.
Has the disc got the Microsoft 25 letter Code stamped on the disc itself?
I guess I know the answer already.