Why wont my PC run 24/7 with A Digital Video Recorder Surveillance?

Question

Im using a Clone PC, Intel Pentium 4, 512mb memory, 80 gb hard disk, ATI Radeon 256 mb video card. It records for at least 15 hours, and when i get back to the computer, its like it rebooted because it is in the welcome screen. OS used is windows xp

Answer 1

Are you recording all the time?
What is your bit rate? (is it running out of disc space?)

Are you sure it rebooted and not went to screen saver mode ? (which depending on your setup can bring you back to the Login screen).

What is the time stamp of the file?
How robust is the application that records? What is the max. file it supports? Perhaps when it reaches x GB of storage it stops.