Specs: No overclocking P4 3.0G HT Northwood stock cooling Asus P4P800-E Deluxe 1GB Kingston Value (2 x 512, single ch) Maxtor 6B200R0 200GB 16MB-cache ATA133 - primary IDE 1 LG 16x/16x DVD burner - primary IDE 2 MSI GF5600 128MB AGP Floppy drive Enermax 460W dual-fan Cooling: 2 x 80mm intakes, 1 left TT ufo 90mm exhaust (can't be reversed), 1 rear 90mm exhaust Temps: CPU 36'C MOBO 31'C idle; 45'C & 32'C on heavy load The gaming/multimedia rig has been up for a few months. It plays all kinds of 3d games for as long as I want. No problem installing XP Pro. P4P800-E D gave me random errors such as no post, no hard disks detected, etc. initially. However, it had since stabilized to the point of "perfection" (quick cold boot in a min instead of a few; no random errors) until after I installed a new, but similar LG 16x/16x DVD burner (was LG 16x/8x). It burns anything fine & dandy. When I try to reinstall XP, XP CD will boot up, say it's checking hardware in black screen, blank the screen, blink DVD burner a few times and light the hd LED constantly. At which point, the computer won't respond to anything other than power off, soft & hard resets. Now I have tried all sorts of BIOS settings including defaults, RAID as IDE. SATA on & off. Even updated BIOS & DVD firmware. Then downgraded BIOS. I don't get it why it stopped being detected by XP setup now. Why not in the first place? If I disconnect hd, XP CD will go to the blue setup screen and tell me there's no hd. Same thing with another DVD drive. Nah, F6 won't work for me as it's an ATA hd and there's no chance for pressing F6. The only solution I found is to connect the ATA hd to Promise ATA133 RAID and set it up as IDE in BIOS. XP setup will work perfect. I suspect XP is unable to find the hd in such a complex motherboard. This morning I fiddled with BIOS again and it couldn't find the installed XP anymore. Turned off IDE bus mastering. I'm back in biz. Oh yeah, I have googled for 2 weeks, and been at the end of my ropes. I'm open to any ideas, other than spending $$$. If I can't get it work like before, I'm going AMD64. The P4 mobo seems to beat my friend's AMD64 rig (6+ hours convert for a 3-hr avi; didn't finish) when encoding audio & video. My P4 takes about as long as the actual video plays to convert to another format. Though he always brags about his 3dmark score. The funny thing is I converted him to AMD. I never had this XP setup freeze with any AMD board I had, FWIW.