So, I spent half a day struggling why my windows XP won't start on any of the safe modes with similar symptoms you all have been seeing. Here is what worked for me on HP pavilion.
There is an option F11 when you boot the system. It takes you to Restore manager by HP via RAM something option. Select Advanced Options for Restore Manager.
A. I first selected the option to back up my files (Photos and Personal Docs/Files) on DVD-R drive. This takes about 1.5 hr to finish but is a worth-it safety step.
B. Rebooted the system, pressed F11, and selected the option to restore system to an older time. Restored the system to 20 days ago. I had tried restoring to two days ago but saw similar problem with it. This worked like charm and kept all my documents intact.
C. There is another option to restore to factory settings and I had intended to go all the way to original factory settings, if option B had not worked. In such a case, my backup DVDs from A would have come handy to restore all my Photos/Videos/Personal files back.
So, the problem seems to be the corruption of a system file and could be attributed to any of the programs I downloaded from the Internet such as DVD Fab in the interim.
Try these 3 things if Windows XP won't boot
1: Use a Windows startup disk
One of the first things you should reach for when troubleshooting a Windows XP boot problem is a Windows startup disk. This floppy disk can come in handy if the problem is being caused when either the startup record for the active partition or the files that the operating system uses to start Windows have become corrupted.
To create a Windows startup disk, insert a floppy disk into the drive of a similarly configured, working Windows XP system, launch My Computer, right-click the floppy disk icon, and select the Format command from the context menu. When you see the Format dialog box, leave all the default settings as they are and click the Start button. Once the format operation is complete, close the Format dialog box to return to My Computer, double-click the drive C icon to access the root directory, and copy the following three files to the floppy disk:
After you create the Windows startup disk, insert it into the floppy drive on the afflicted system and press [Ctrl][Alt][Delete] to reboot the computer. When you boot from the Windows startup disk, the computer will bypass the active partition and boot files on the hard disk and attempt to start Windows XP normally.
#2: Use Last Known Good Configuration
You can also try to boot the operating system with the Last Known Good Configuration feature. This feature will allow you to undo any changes that caused problems in the CurrentControlSet registry key, which defines hardware and driver settings. The Last Known Good Configuration feature replaces the contents of the CurrentControlSet registry key with a backup copy that was last used to successfully start up the operating system.
#3: Use System Restore
Another tool that might be helpful when Windows XP won't boot is System Restore. System Restore runs in the background as a service and continually monitors system-critical components for changes. When it detects an impending change, System Restore immediately makes backup copies, called restore points, of these critical components before the change occurs. In addition, System Restore is configured by default to create restore points every 24 hours.
To use System Restore, first restart the computer by pressing [Ctrl][Alt][Delete]. When you see the message Please select the operating system to start or hear the single beep, press [F8] to display the Windows Advanced Options menu. Now, select the Safe Mode item from the menu and press [Enter].
Once Windows XP boots into Safe mode, click the Start button, access the All Programs | Accessories | System Tools menu, and select System Restore. Because you're running in Safe mode, the only option on the opening screen of the System Restore wizard is Restore My Computer To An Earlier Time, and it's selected by default, so just click Next. Then, follow along with the wizard to select a restore point and begin the restoration procedure.
I hope this information will be useful to resolve your issue regarding Windows XP booting!