Hi guys, got some issues with a motherboard, wonder if describing my symptoms can help me make a decision ... It's an MSI6714, designed for a PentiumHT CPU. The one it's got is a 3.06Ghz. I inherited it, without memory, HDD, or a power supply. The Graphics card is an nVidia GE440MX. I put a 300W PSU in, and 1gB (2x512Mb) of memory I had lying aroung - it's Samsung DDR200. Machine booted (from CD) fine. However running memtest caused it to go into a weird power cycle after a few minutes. After hours of fiddling I found that using just one 512 Mb stick seemed to fix it - memTest seemed to run all the way through - although I thought it a little odd the machine was off the next morning. Installed XP and Linux (Ubuntu) no problems. Been running for 3 weeks now, seemingly OK. Ubuntu seems a litte unstable, (but that's software for you). Yesterday, Ubuntu wanted to do a software update - AFAICT the Kernel, so I started it off, it downloaded some files and started installing. Then, all of a sudden, the shutdown box (log off, shutdown, restart etc) appeared. I quickly clicked "cancel", but it kept popping up. Then, without warnng the machine shut down. After that, it wouldn't boot into windows or Ubuntu. Got halfway through and just shut down. I tried booting into Ubuntu-recovery console, but that shut down too. I opened the case, and felt the CPU - it was about 35 degrees Celcius. I swapped the 512 memory stick for the one I'd left out, made sure it was engaged properly, and tried again. This time the machine booted perfectly. I had to reconfigure Ubuntu, and way we went. How likely is it, that I'm dealing with a faulty or mismatched memory module(s) ? Three years ago I spent a week at work trying to install XP on a machine that kept crashing at random points. Even when the install seemed to go OK, it would lock up, and freeze, or switch off by itself. In the end "Prime95" and Memtest wouldn't even load, and it was obvious it was the memory. Another possibility I can think of is a faulty heat-sensor. Unfortunately the machines BIOS is very basic, and gives me no access to the PC health screen, or memory timings. Is there a software way to access these settings. Failing that, given that *something* made the machine want to close down, then is there a log file to dig into with Ubuntu ? Finally, there's the mobo itself ... however my gut instinct is that given it's shown itself capable of booting, running XP for hours on end and burning a DVD, that this is the least likely possibilty. I guess one school of thought is start with some new memory - you can save it if you need a new mobo. In the event I need to get a new mobo, is it work getting a bare one and re-using my P4 from this one, or is there a much better CPU I can use nowadays. I'm not religious about Intel or AMD, but wouldn't like to go for a cut-down one, unless someone can convince me it's better than a P4 Thanks in advance guys