1.
Slave Hard Drive. If your data is important to you, slave the hard disk drive to a working computer and
copy data to backup device.
Slave a Hard Drive2.
Recovery Console. If you have a suitable Windows XP CD (or have made the six volume Windows XP Setup floppies), you may boot to recovery console and attempt to use "chkdsk /p /r" to verify and correct file system and bad sector errors. This can be a slow process.
Do not interrupt or abort it before it completes. Upon successful completion, see if you can boot to Safe Mode. Is so, see if you can boot to Normal Mode.
Recovery Console CommandsIf recovery console permits you to successfully access "boot" volume and successfully run "chkdsk", but still not boot; you may have to repair the volume boot record and/or Master Boot Record (MBR).
If you use recovery console, let us know your status.
3.
Hard Drive Diagnostics. Most hard drive manufacturers provide "free" downloadable diagnostic software for bootable floppy or CD. Look for download link on their website. Start with the nondestructive diagnostics to test the hard drive and its disk surfaces. It's possible your hard drive has failed. (Or your data cable needs to be reseated or replaced).
4.
Repair Install. Or per ADG's advice, with the appropriate Windows XP CD, you may do a repair install.
5.
Current Status. Upon system startup does it still go to "safe mode screen with several options"?
6. Is your computer a desktop or laptop? Did it come with a "Restore/Recovery CD"? Did it come with a preinstalled "Recovery Partition" on the hard drive?