Hey. I have another IRQL_NOT_LESS_OR_EQUAL problem again. My first time having it was about a year ago but I fixed it. This one is different though. First, I got the message from the blue screen of death and then my computer shut down. Now when I try and reboot it, it goes to a screen saying it detects a keyboard and mouse and so on and at the bottom it says "Primary Master Hard Disc Error, Press F4 To Resume". I press F4 then after about 30 seconds of waiting on a black screen it shows another black screen saying " Reboot and select proper boot device or insert boot media in selected boot device". Then I have to restart and go through that same process again. So then I inserted my windows disc and was ready to format my drive and reinstall windows, but when it was on the blue screen to choose to repair windows or format and reinstall, I chose repair first but then it says I have to quit this setup because windows does not detect a drive installed on my computer. I also tried to format and reinstall and got the same message. So then I restarted and went into my BIOS and my BIOS is registering that it detects my hard disc because it says the size of it and the name. So it can't be damage to the hard disc. About 10 mins before I got the blue screen of death my antivirus program detected a trojan virus too so I don't know if this may have caused the problem but it shouldn't because as soon as it detected the virus I ran a bootime scan and deleted all infected files. IRQL_NOT_LESS_OR_EQUAL is usally a software problem, isn't it? how can I fix this problem? I can't even get onto my computer. Someone please help.

i had a similar problem (windows detected my HDD but wouldnt boot/re install) i replaced the IDE cable and it worked... make sure it is plugged in, if it is then try replacing the cable (make sure there are no damaged pins)

also, remove any new hardware

if that doesnt work, try your HDD in a different computer (as slave) to see if everything loads ok.

Hope this helps
Mike

p.s the trojan would not stop you from doing a clean install of XP