We have been running Vegas 8 on two computers for months with no problems. it is very stable. We are running it on Windows XP Pro with all the latest updates including SP3. Speaking from experience with ONE big problem check to see what anti virus software you are running on the machines that you are having problems with. We are using SPYBOT and AVG. We use to use McAfee and our machines were way too sluggish and way to unstable. We would get about 81% through a render and the render would just stop dead. Not sure what was happening but the anti virus software was interfering with the render after a certain point. It took me a couple of days to get the McAfee completely off my machine and I had to do some registry editing to get all its tentacles out of the registry. Also SATA drives are the best you can use for editing and rendering and we have been using the new SEAGATE drives with no problems. FWIW