PC Restarts when Zone Alarm Install Starts

Micron PC
Win XP Home Edition Version 2002 with SP 2
Intel Celeron Processor @ 467Mhz
128 MB ram

I downloaded the current update for Zone alarm yesterday.
When installation starts the pc automatically restarts.
I deleted the zone alarm and re-downloaded it.
Upon attempting to start installation again the same thing happens and the computer restarts every time Installation begins.
I've downloaded a couple other programs since this and they both installed without any problems of restarting.
Any ideas on this?