I am having a very slow boot up time. Everything is normal until the computer gets to the windows XP screen. It stays there for about 2 minutes and then the screen goes blank and it takes about 40 minutes to load the desktop. After that the computer goes back to normal.

Here are my specs:
Soyo PX400 Ultra
512 megabytes of memory (no brand name)
Pentium 4 1.70 Ghz.
DVD RW from Liteon
IDE C: 60 Gigs HDD 0
IDE G: 160 gigs 2 disk array RAID 0
Ge Force MX400 video card

Please help as I am also getting error messages like "IRQL Not less than or equal" and "driver power state failure".

Thanks in advance.
kshroben

usually when a windows machine is behaving slow, it is because the system is bogged down by malicious software and/or a fallible registry. on the other hand, nons of that is likely to cause the bsod you mentioned. this website explains your stop messages what is the brand, model, and watt-rating power supply you are using?

The power supply is a MAX Switching Power Supply Model LC-B400ATX, 400 Watts.

attempt booting windows into safe mode, and see if the problem persists. to do this, press F8 as windows begins to load, and select safe mode from the menu.

Thanks for the reply. I tried booting into safe mode but was unable to. The computer will tryo to load the basic drives and will freeze at MUP.SYS. A while later, I get a blue screen with IRQL NOT LESS OR EQUAL error or "Driver_Power_State_ Failure" error.

An in place upgrade will hopefully sort you out.
See Rick's guide

if that doesn't fix it, you can reasonably deduct that you have a serious hardware problems in that case i advise you to suspect the mobo/psu first.