NEC ND1100a DVDRW+ & Win XP

Hi, I am having trouble playing DVD movies on my ND1100a, my whole system crashes after a few seconds: Here are the psecs of my PC:
P4 2.8, 1GB RAM, Radeon 128DDR graphics, LG 48 CDRW, ND1100a DVDRW+, WinTV card.

Running on a Win XP Pro OS. I have also installed:
Nero, WinDVD and Hauppage WinTV software.

Does any one have an idea why the system crashes when I try and play a DVD?

Your help is much appreciated. Apologies if I might have posted in the wrong forum…