Place the first recovery disc (or an operating system disc-sorry you didn't tell us which operating system you're using or the make and model of the computer) in the DVD/CD drive, then restart the computer.. It should boot from the disc and allow you to run a "repair" install OR.. toformat and reinstall the operating system back to it's original factory state.
Once it's reinstalled, you can use your BACKUP files to replace the personal documents, music, pictures, etc.
Hope this helps.
My computer crashed,it said that I have no proper HDD. It will not let me in any of the modes. There is no noise.Every thing was working fine.If I need new driver's where can I get them and how can I install them.Thank you for any help you can give. P.S. The blue sreensaid Technical information***STOP: 0x0000007E (0x000001D,0x8A4204E0,0xB84C72D8,0xB84C6FD4). Also I think it's an LITE-ON DVDRW SHM-165P6S NSOK THAT MAY NOT BE THE HARD DRIVE. Ihope you can help