Random Lock-ups/Freeze-ups; It's NOT the Power Supply... My system stats: P4 2.6Ghz, Abit IS7 mobo, 1 gig dual channel Mushkin DDR400 RAM, 16x dvd-rom, 8x dvd-rw, 120 gig ultra 100ata 7200 rpm Western Digital Hard drive, 200 gig Seagate ultra 100ata 7200 rpm hard drive, Raidmax 420 watt power supply, 5 internal 80mm case fans, 3.5 inch floppy, 10/100 nic, hauppauge wintv card, ATI Radeon 9600XT 128mb video card, 17 inch NEC crt monitor, canon 3000f scanner, canon s600 printer. My problem: For months, I have had system freeze/lock-up problems. Suddenly the mouse just won't move, keyboard has no affect, and I have to reboot to get the system to work again. Then sometimes, I'll turn on the computer and it will say "no hard drives found" or "no cd drives found" or something like that. I'll then reboot yet again and then it'll be ok for a while. Sometimes this occurs after only a few seconds of being on - other times the system can run fine for weeks. I built this in December 2003. In March this year I started having problems with the hard drives powering on and off while the computer was on. I stupidly thought the IDE channel on my previous Albatron mobo was shot; spent $170 on an Abit mobo with an extended warranty only to discover the problem reoccurring about 3 weeks later. Then I thought it was the hard drive (the Western Digital - I just bought the Seagate a month ago) going bad, so I RMA'd it for warranty service after they told me the symptom was caused by either the power supply or the hard drive itself. 2 weeks after getting the replacement hard drive installed, problem reoccurs. I've also hooked the monitor and tower on completely separate electrical outlets to make sure it wasn't my house's wiring. Nope, problem occurred 1 hour ago again. I am at my wits end here people. This is the 4th computer I've built; the previous 3 have been perfect. Please tell me what in the world could be causing these random lock-ups. I think it is the power supply. I have Abit software that monitors the 12V, 3.3V, and +5V lines and they never show anything other than just slight .1 difference up or down, but then again, once the problem starts, the whole system freezes, so I guess the Abit program would never show any problem given the situation. Tell me, is it the power supply? Sorry for the extremely long post, but folks, I'm going crazy here trying to diagnose this!! If it is the power supply, do I need more watts than 420? I've seen a 480 watt Thermaltake with something called "active PFC" that while it is expensive, looks good.