Problem

Hi!
I have a dell 4550 with the following components:

-p4@2.4ghz
-60gb WD hard drive
-1280mb ram
-thermaltake 420watt psu
-intel 845PE motherboard

My mom just experienced a problem with it this morning with the system not booting to normal windows... It is running xp Home.

Here's what happens.
I turn it on, the system goes through normal BIOS procedures and gets to the windows xp loading screen. It loads some of windows, I know because the hard drive light is working, then the light stops and all HD activity stops and the windows bar keeps right on moving...
That rules out the whole system freezing..

Now here's the catcher: the system WILL boot in safe mode if turned off and back on, but not normal xp....

Thank you to anyone who can help.