I had Windows 2000 pro on my system. Shortly after I setup a wireless router on it, my computer would startup, get to the logon screen just fine. Then it would shut down and start all over again. It did this about 6 or 7 times. Then one time after listing my devices it froze. Upon restarting it, it said "Missing Operating system" could the router and network setup have caused this? I've installed XP on it but I don't want the same thing to happen again. So if you have any insights please let me know. Illy

you may need to check in your bios that your first device seen by your computer is your hard drive

It is possible, if you had to install any new hardware on your win2000 computer that required software. It sounds like there was either a hardware or software conflict, probably related to what you had just done. Without knowing what was listed on the "Blue Screen Of Death", it could have been software and/or drivers fighting for possession over the same memory location, or it could be your hard drive has a bad sector(s), or you may have a bad location on your memory modules. There are so many things that could have caused this, they can not be listed here. If it starts to mess up again, try hitting the "pause" key when the "BSOD" appears and write down what you see. It will help to pinpoint the problem.

First device in boot order should never be hard drive, if it is then cd and floppy can never be used as boot devices. I cannot imagine how a router could cause such a thing. That sounds more like a software conflict. I have seen that happen with Ghost and Kaspersky AV, it is a known problem. What if any software had you installed recently, or perhaps with the router?