|Step 1: Check the BIOS to make sure the hard drive is being properly recognized.|
"He does not have any disc to fix it , it came pre installed with Windows Vista"
The "Vista disc" is stored on the HDD. Your friend should have created the disc(s) the day he purchased the computer. If the HDD shows up in the BIOS he may be able to do a factory restore from the recovery partition, but he will likely lose all his files, photos, word docs, programs, etc. Hopefully he has backups? See the following:
If the above doesn't work, try starting the computer from a full shutdown & tap the F11 key.