BSOD - IRQ USBOHCI error. Help please???

Hi.
Just recently acquired another PC, ASUS T2 running P4/3GHz, 512ram, 120gHD, Nvidia 6600 graphics, 4 USB, 2 front, 2 rear.

Had to remove Nvidia as previous owner had it set up to an ATI Radeon and it frightened the life out of my little 17" CRT - every time I booted up as soon as it hit Windows the poor little thing would throw its hands in the air and shut down! Plugged the CRT into the on-board graphics which is running it fine.

The PC had been used as a gaming machine and came loaded with XP Pro 2. I loaded it with my software, Office 2000, etc., Xyxel modem driver, HP 1200 printer.

The first BSOD came just before I switched the machine off after installing the software and drivers. I closed down and rebooted and apart from the error message it seemed fine, but I get the BSOD intermittently. Sometimes 2 or 3 days apart, sometimes within a few minutes. Usually I'm not doing very much and a couple of times I was not at the machine at all.

DRIVER IRQ NOT LESS OR EQUAL
Stop 0x000000D1 (0x80000028, 0x00000002, 0x00000000, 0xF7B7739)
usbohci.sys - address F7B9F739
base at F7B9E000, Datestamp 3d6ddc30

The printer and modem were plugged into the rear USB sockets. I noticed that when the machine was off (although it has residual power to the front LED), the DATA light was still on on the modem. I changed the modem to a front USB and now the light goes off with the machine - problem with the rear USB sockets? The printer is still plugged in to a rear socket.

Another odd thing I have noticed is that the keyboard light is also on when the machine is off - not normal surely?

I would welcome any ideas..............

ok that msg says something is wrong with your usb modem driver so get a new driver for it and is the keyboard usb 2

The modem works fine when attached to the front usb slots - it's the rear usb connectors which seem to have the problem (it worked ok on the rear ones - it's just that the data light on the modem stayed on when the machine was turned off which was pretty unnerving - this doesn't happen when I plug into the front usb's). I have removed both the modem (which is now connected at the front) and the printer from the rear usb slots but I am still getting the BSOD's.

I am wondering whether it might have anything to do with me having removed the Nvidia card, but not technical enough to find out.

The keyboard is PS/2 plugged in to the MB connection.

Maybe there is a problem with the MB as the keyboard is still on when the machine is off.

I tried to look at the debug files but don't have anything that will open them.

Yesterday it BSOD'd 4 times!

ok then you need to look on the device manager and see if there are and yield looking signs by the usb port drivers

Sorry, didn't understand what you were saying ("and yield"?).

I had already checked the Device Manager - there are no error messages attached to any of the USB slots or the Keyboard.

your motherboard isnt set up right its a interrupt conflict

Bootup without a keyboard, or use a PS/2 keyboard. If the problem is with the USB driver, than having something plugged into a USB port during startup could cause the crash.

Also make sure all of your system drivers are set up properly, specifically for the problem product. Unplug everything that is in the USB Port and then see if that shows up again. Keep re-attatching things one at a time or test out slots with the same problem. You should be able to come to a conclusion with this method.

As I mentioned earlier it is a PS/2 keyboard anyway. The problem seems to be attached to the rear USBs - the front ones seem to be ok.

The crash does not happen on startup - it is totally random, maybe even hours after I have booted up but the STOP message is always the same as mentioned in my first posting, connected to the USBOHCI.sys. Sometimes it doesn't happen for 2 or 3 days, but once it happened twice within 10 minutes. I am not doing anything specific at the time and sometimes not even at the computer at the time so it must be triggered by some process within the PC itself. I don't have a clue what the USBOHCI is, let alone disconnect it! There is nothing plugged in to the rear USBs at all. There is an IRQ conflict there somewhere but I don't have clue what is triggering it, which is why I hoped that someone with some technical knowledge would understand enough from the information I have given to know what is happening and why!

I have also now found that the PC 'freezes' at times, doing certain minor actions but not closing programs or even closing down. In these cases the only thing I can do is switch off. It might be an IRQ again which has caused Windows to stop but not get as far as the BSOD.

Getting frustrated with it now...............