възможни причини:
"Cause:
Computer is booting from a non-bootable source.
Computer hard disk drive is not properly setup in BIOS.
Corrupt NTLDR and/or NTDETECT.COM file.
Misconfiguration with the boot.ini file.
Attempting to upgrade from a Windows 95, 98, or ME computer that is using FAT32.
New hard disk drive being added.
Corrupt boot sector / master boot record.
Seriously corrupted version of Windows 2000 or Windows XP.
Loose or Faulty IDE/EIDE hard disk drive cable."

Ти как разбра че се осрал уиндоуса, боб ли хвърля?

ползвайте GOOGLE, братя, там е истината...