problems with my old pc

i gave my old pc to my mum, and before i give it to her i reinstalled windows xp, but a few days after i gave it to her, she started having problems

specs -

windows xp pro
dell dimension xps t500
intel pentium 3
320mb ram

problem 1 - the pc frezzes at shut down

problem 2 - pc sometimes doesnt start sucessfully

problem 3 (new problem just started) - sometimes the usb ports, printer port, keyboard and mouse ports fail, and theres nothing to control the pc with.

problem 4 - sometimes when you turn the pc on and go to login the pc automicly says windows is shuting down.

i was going to try reinstalling windows xp again, but i cant find my product key. can anyone help

Have you tried safe mode?

thanks for replying but just got it working, just reinstalled windows xp again, working fine now

etones
For future reference.
>> i was going to try reinstalling windows xp again, but i cant find my product key. can anyone help

Download:
Belarc (http://www.belarc.com/free_download.html)

Amongst the information that is supplied is your product key. Save the page.