Almost new system locks on 50% of bootup
I have a a fairly new HP pavilion. It is running WIn XP Home Edition. When it starts up it will go to the users screen and you pick which user is logging in and put their password in. About half the time you boot it up it just about locks up at the sign on screen. It takes forever. If I shut it down and reboot it may work fine, it will go through the log on screen as if it were brand new. Then I shut it down and reboot it and it may or may not lock again at the sign on screen. It has a 2.6 p4 and 512 DDR with a 120g hard drive.
What I am also seeing is that when this happens the keyboard and mouse lock up, but the cursor is still flashing at the password location and if I just touch the power button it goes to the screen that windows is shutting down. So the system is not really locked up but something is locking the mouse and keyboard.
Any ideas what is causing this to happen to the mouse and keyboard?
I have run updated antivirus, no viruses present. I have run Spy Sweeper and cleared all cookies and adware. Any ideas???