Hi- Just new to these boards - discovered them in my search for answers. I've read some similar posts on here regarding startup problems, but my situation seems a bit different. The issue - intermittent problems with computer not powering up, i.e. nothing happening when I hit the power switch. I had the PSU tested and it is OK. I have a green light on the mobo. I get occasional power up, seems random - e.g. after turning power bar on or off, changing to a different plug, trying different power cable - but those also don't always work. Other factors - leading up to this I had two blue screens of death at startup a few days ago, something about "unmountable boot volume" and "session 3 initialization failed" I also had a system freeze at one point, never happened before. Ran chkdsk at startup and discovered 4 bad sectors. I then began thinking it was a windows problem, so reinstalled windows on a 2nd (formerly slave) HD. Original HD still connected. Thought it was fixed (5 or 6 startups with no problems - i.e. powering up when I hit the switch) but it has gone back to not starting today. I had the system checked out at a computer shop yesterday, they told me mobo OK and just those 4 HD sectors that are bad, but I'm not so sure....(wasted 25 bucks to have them tell me what I knew, nothing more) Specifics: Alienware system, P4 1.8, Intel board, 1gb of RAM (4x 256), ATI Radeon 9600, Win XP Pro. Not sure if any other info is needed. Recently added a PCI USB 2.0 card, as well as an external 4 port USB hub (plugged into that USB card). No other recent hardware additions. I'm pretty desparate now - not sure whether to test individual components further (e.g., mobo, RAM, video card) or just resign myself to building a better machine. However I don't want to use a suspect part and create the same problem in the next one! e.g. a USB card problem that might have zapped the mobo. Any advice would be greatly appreciated, thanks.