Ok, appreciate i'm a newbie here but any help would be appreciated as I am at my wits end. Basically I built a new PC for my bro's birthday pressie. I used a MSI 648Max board with a 1.GHz P4, 1.5 Gig of ram, 128Mb Geforce 4 MX440 with 8X AGP, a 250GB seagate HD (partitioned to C and D), a LiteOn CD RW and a generic DVD rom drive. It also has a Wireless g card and a Via 5 port usb PCI card in it. Everything was fine when I built the machine and i ran it all day on the internet and doing downloads to make sure it was stable. It handled all the stuff i threw at it no probs. BUT when I moved it to my bro's room it started having probs. First it was fine and then for no apparent reason it blue screened with a driver IRQL LESS THAN OR EQUAL bad calland did a mem dump. We thought that was a one off but the machine then refused point blank to even post. I progressively removed the extra cards and drives untill i was left withjust the cpu, graphics card and ram connected to the board. Still no boot so i removed the graphics card at which point i got a beep code. Refitted the graphics card and the hd and the machine booted and ran fine. Progressively reconnected everything testing for boot at every stage. No problems, so i thought that was that. Next day I came home and my bro told me the machine had blue screened again but diff message this time. Tried it and it wouldnt post. Now here comes the weird bit, I moved the machine back to my room exactly as it was and hooked it back up to my kvm switch. Hit the power again and the machine booted first time! (I hadn't touched anything!). Checked everything in the bios and the sys settings in windows and all looked ok. Took it back to my bro's room and it then refused to post again! I tried clearing the CMIOS using the jumper and after 2-3 clears the machine booted ok. Checked everything again in windows and all looked ok. Again came home the next day and the machine had died again! This time it was the driver IRQL error on the bluescreen. Tried unplugging the IDE channel that had the CD and DVD drive on it and after a CMOS reset the machine booted fine. Shut it down and reconnected the CD drive only, machine was fine. Then tried connecting the DVD drive at which point the machine blue screened during boot. Thought that pointed to the DVD drive being suspect so I left it disconnected and rebooted. Machine ran fine the next day and then blue screened with the message exception not handled and dumped the memory again. Tried a CMOS clearand got the post back but couldnt boot. I tried a systen restore with a w2k CD and it turned out that the C:\ partion file structure was knackered. Reformatted the C partition and reinstalled 2k. Did sp4 install and all updates, installed programs and test ran everything. No problems. Put the machine back in my bro's room and it was fine. Came home tonight and the machine simply wont post now. It was shutdown fine and seemed to have run fine today. However it now wont post even after disconnecting everything and doing a CMOS clear. I've tried a different graphics card and the machine booted once with that. Shut it down to reinsert pci cards and it now wont boot even in my room after a CMOS clear and leaving the battery out for ages. I have noticed for some reason the machine wont do a restart from windows (i.e. wont post after a restart command has been issued from windows). Also this means I cant alter the bios settings because when I do a save and exit from the BIOS the machine wont post and the only way to get it back is to do a clear CMOS with the jumper, after which it normally works. Apologies for the really, really long post but this is driving me round the bend as I really can't figure out what is wrong! Any ideas? Thanks in advance

What size and make is the PSU? A lot of problems are due to an inadequate power supply. Keep Smiling It makes them think you're up to something...

Sounds like it always works in your room, so I would put the machine physically in his room but use a long extension cord so that it can be plugged into your room - see if it works. It does sound like a power issue which means it could be his wall outlet, the psu itself, or the motherboard.

PSU is a P4 Codegen rated for 420W. Funnily enough when its in my room it runs off a 4 way multi plug (with my power hungry beast running off it at the same time) but in my bro's room it runs directly off the wall. Would the psu cause driver IRQL errors?

The AC circuit in your brother's room may be overloaded, possibly Window AC, frig, Etc. Check voltages at the wall under load.

Ok thanks guys. Will try it elsewhere in the house when I get a chance, if I can ever get the thing to run again! Air con?!? don't need that in the UK :-D lol! Just from curiosity can someone explain why a dodgy AC cicuit would cause windows to BSOD with a driver IRQL error?

Different components in the computer run on odd voltages that can be tweaked by .05V at a time. Easy to see how 10 or 15% voltage drip can cause problems. That kind of voltage drop even plays havoc on appliances like refridgerators. So, if the memory isn't getting the correct voltage it is easy to see how it could malfunction. Same goes for all the components.