Wild Reboot During Ripping

Hi all,
my first thread on this poderous forum…Nice one really.

Well I suppose I’ll be the only “lost in la Mancha” to ask this question ie:

why my pc reboots hardly when I try to rip a DVD ?
why it rebooted when I tried to uninstall RAT DVD ?

-I have tried it with a non protected DVD
-I have used Any DVD in addition
-I have Windows XP SP1
-Nod 32 anti virus
-Spyware blaster and spyware guard installed in background
-Ewido active in background
-Zone Alarm Firewall
-Direct X9
-Windows Media Player 10

What else could I say exepcted :

In advance my best thanks for your kind replies and please be so kind to re-route me to a link or a thread which already explains how to get out of the tunnel

Cheers
Tony