My computer uses the AMD 756 PCI bus master dual IDE controller. I really don't know much about it, but my device manager is saying that the primary & secondary controllers aren't working properly. It says for both:

"This device is either not present, not working properly, or does not have all the drivers installed. (Code 10).

Try upgrading the device drivers for this device."

First I tried having windows search for the best drivers, but after it said it already was using the best, I tried to find the drivers online, but with no luck.

What I don't understand is the AMD 756 PCI bus master dual IDE controller is working, but the others aren't. I also don't know why this just seemed to happen out of nowhere...my computer was working OK besides a problem with my CDrom (I can't get it to open...it's had some problems like that since my husband installed a new hard drive, but now it won't open at all), which I think has something to do with all this because it all happened around the same time, but after restarting the computer a few days ago, this whole problem happened.

I also don't understand why, after I reinstalled the drivers the last time, the device manager popped up another master controller and another secondary controller (both the same as the ones that were already there), and I can't delete them! Also, I don't know if this has anything to do with all of this, but I think it does, seeing as how my computer only popped this up after I started having all these problems - in the System Properties performance tab, I have these sentences listed:

Compatibility-mode paging reduces overall system performance.
Drive C is using MS-DOS compatibility mode file system.
Drive D is using MS-DOS compatibility mode file system.

When I click on details for the first sentence, it says "Windows was unable to identify a real-mode driver or memory-resident program loaded in your Config.sys or Autoexec.bat file. You will see another message that lists the name of the driver or program causing the problem.
Because Windows could not identify the driver or program, it has switched to MS-DOS compatibility mode to ensure the program will run. However, this decreases overall performance. To improve performance, remove the program or driver causing the problem, or contact its manufacturer for an upgraded version."

For the next two sentences, it says "This problem often occurs on more than one drive. Usually it is caused by a driver listed in the Config.sys file that Windows does not recognize and that is related to the message Compatibility mode paging reduces overall system performance. If you see both messages, see the Help for the Compatibility mode paging reduces overall system performance message first.
If you only see the message Drive X is using an MS-DOS compatibility mode file system on one drive, that drive is using an MS-DOS compatibility (real-mode) driver, which may reduce that drive’s performance. Contact your hardware manufacturer to see if an updated driver is available for your drive. If not, the drive’s performance may be less than optimal, but you can still use it."

I've reinstalled drivers like it mentions, but like I've stated, that hasn't worked. Any suggestions ASAP would be greatly appreciated, because I can't seem to make sense of any of this! Thanks.

open your computer, mac sure the card is seated fully (make sure you are not static otherwise you may zap your hardware (touch a piece of metal first or wear a anti-static wrist band connected to something metal) if it is you may just want to take it out and reseat it fully, then try unplugging your computer and removing all power from the system (on dells that's done by holding down the power button once the computer's unplugged for 5 seconds, read your manual to find out how to do this, if it's a dell this method should work for you), then plug it back and start it up and see if that fixes it, you may also want to upgrade to xp pro, oh and goto windowsupdate.microsoft.com and install all updates listed on the site - good luck!