you could try pressing F5 to refresh the screen but i doubt it would work, it sounds like the boot up is hanging perhaps at the welcome sound or maybe the explorer is having conflicts (not internet explorer).
maybe you need to flash the bios (but i would use this as a last resort), i have had occasions when the boot up has not waited for a device to start before it moves to the next one, explorer again i seem to remember and a bios flash has cured the problem but as you may or may not be aware, a bios flash can also cause your pc to fail hence the last resort warning.
you mention system restore, but has this problem always been there, or just lately (maybe some software installed/uninstalled has corrupted some system files, then it would pay to run system file checker (sfc)
click start, run, and type
note the space after sfc, you will need your winxp cd in the drive (or restore disc). If the sfc finishes without warnings then all was found to be ok and you would need to look elsewhere if the symptoms persist.