Critical Error: Hard drive missing, hard drive not found. Hard drive error.

Hello,
When I start my computer HDD request starts automatically, telling me there 11 errors with my hard drive. After i perform the deframentation, it fixes 6 and 5 remains. I can use my computer for about 10 to 15 minutes before it makes me restart it. I was just wondering if there's any way of fixing this?
Thanks

Hi,
If you're using Windows Vista, do you have that DVD ? I'll perform few repairs.

no i dont have the DVD.

Can you borrow copy of Windows Vista from your friends ? It doesn't need to be original.

Pleas follow next instructions.

• Go to Start > My Computer.
  
• Right click on your C: partition and go to Properties.
  
• Go to Tools tab and choose Error Checking.
  
• Mark both options inside and press Start.
  
• After checking, please restart your computer.
  

Let me know results.

I've done this, numerous times.. always the same 11 errors, and it fixed 6 and leaves 5...
Read time of hard drive clusters less than 500ms- failed to fix
333% of HDD space is unreadable - failed to fix
Hard drive doesn't respond to system commands - failed to fix
Bad sectors on hard drive or damaged file allocation table - failed to fix
Boot sector of the hard drive disk is damaged - dailure to fix.

Okay, please follow next instructions.

• Go to Start > All Programs > Accessories > Right click on Command Prompt and go Run as Administrator.
  
• In Command Prompt type command bellow, and after each one, press Enter to run it.
  

bootrec.exe
bootrec.exe /fixmbr
bootrec.exe /fixboot
bootrec.exe /rebuildbcd
bootrec.exe /scanos

Please restart your computer after this step, and run Error Checking again. Tell me results.

after everyone i type it it says :
'bootrec.exe' is not recognized as an internal or external command, operable program or batch files.

You really need to find Windows Vista installation disc. I can not perform any action without the disc.