I am working on my mother in laws computer so I am not sure what happened when the errors first started happening. She has a Dell and is running XP home edition. When I got the computer and booted it up, I got the following errors: driver_irql_not_less_or_equal and iastor.sys address F861A25F base at F860B000 date stamp 42b2df42. At this point I could not boot up at all, not even in safe mode. I looked up the iastor.sys error and I found an article at Dell ( apparently that is a long running error with Dell computers ) that told me to change the SATA operation setting from RAID Autodetect/AHCI to RAID Autodetect /ATA in the system setup. Once I did that, I was able to boot up. I tried booting in normal mode but after windows loaded, I could not do anything. So I rebooted in safe mode. This article told me to then download and Install the Intel Matrix Storage Driver. I tired to install that but I got an error saying that the system did not meet the requirements and would not let me load it. So this is where I am stuck. When I boot to safe mode, I can open programs and files but not when I boot in normal mode. My SATA Operation settings are still the way I changed them. Any help would be greatly appreciated! Forgot to mention that I ran a virus scan with Norton and everything came back ok. Lisa

Did you Google that filename? http://www.google.com/search?q=iast... Life's more painless for the brainless.

If you aren't using Raid, disable it in the bios. The instruction that you followed earlier might have been just for a Raid system. I doubt if your mother in law is running Raid.

You should disable raid in BIOS. If that does not work, you should download your motherboards chip set drivers and install them, as well as updated raid drivers. I would go directly to the manufacturers website, not Dell's. For instance if you have an Intel chip set, go to Intel's site for drivers.

"driver_irql_not_less_or_equal" That may or may not have anything to do with your iastor.sys error. You can get the IRQL_NOT_LESS_OR_EQUAL error from many causes, but sometimes it can be just because the ram module contacts are not getting a good connection - this worked for me when I got that error: A common thing that can happen with ram, even ram that worked fine previously, is the ram has, or has developed, a poor connection in it's slot(s). This usually happens a long time after the ram was installed, but it can happen with new ram, or after moving the computer case from one place to another, and I've had even new modules that needed to have their contacts cleaned. See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated: http://www.computing.net/hardware/w... For a laptop, you must remove both its main battery and AC adapter before you do that. ....... "This article told me to then download and Install the Intel Matrix Storage Driver. I tired to install that but I got an error saying that the system did not meet the requirements and would not let me load it. So this is where I am stuck." There may very well be different versions of the Intel Matrix Storage Driver - you may need to get the correct version for your Intel main mboard chipset. If you're not sure which Intel main chipset you have, tell us what your exact Dell model number is - it's on a label on the outside of the case.