WinXP Pro BootUp Problem

I have a PC w/WinXP Professional Ver2002, SvcPack 3, Intel Pentium 4CPU 1.7GHz, 512MB of RAM. The problem is that the WinXP boots up in the safe mode, but after several shut downs and or restarts it sometime boots up properly for a few times only before it reverts back to booting up in the safe mode. There are no messages of any kind referring to the problem, except there is an occasional reference to the PCI Serial Port whereby it asks for a driver for the device.

Attempts to install the driver fails and the resulting message is that the hardware couldn't be intalled because the software could not be found. I have no idea what hardware it is looking for. I installed a 2.0 USB card and it works fine.

 

What happens when you try to boot normally?

 

I have been able to reach the boot up screen a few times by repeatedly shutting down and restarting, and sometimes by hitting the reset button. Attempts to start normal does not work; the system boots up in the safe mode.

Thank you for responding.