1. Click Start, click Run, type chkdsk /r, and then click OK.
2. At the command prompt, type Y to let the disk scanner run when you restart the computer.
3. Restart the computer.
4. Chkdsk will run.
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You can use Speedfan to check your temperatures.
You can also check your hard drive and RAM using these programs.
That could be a problem with bad RAM. Please run this check just to eliminate that possibility.
Test your RAM here.
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Run hard drive diagnostics: tacktech.com
Make sure, you select tool, which is appropriate for the brand of your hard drive.
Depending on the program, it'll create bootable floppy, or bootable CD.
If downloaded file is of .iso type, use ImgBurn: imgburn to burn .iso file to a CD (select "Write image file to disc" option), and make the CD bootable.
For Toshiba hard drives, see here:
Note : If you do not know how to set your computer to boot from CD follow the steps here