Computer not booting when USB device attached

[wrighty1980]

I've just rebuilt a fairly elderly PC, which is now using Windows XP professional. I'm very pleased with muself, as I'm normally hopeless at these sorts of things and it is running fine except for one thing. It will not boot if there is anything plugged into any of the USB sockets as it is switched on (it will not even run the BIOS) - they can only be connected when windows starts loading. This was not a problem on good old Windows 98. Can anybody shed any light? Thanks!

[j2buttonsw]

I can't help thinking it has nothing to do with the Windows XP as the problem occurs before the OS is even installed ie it won't boot to the BIOS! Maybe the USB ports are faulty? You can replace them with a more superior USB 2.0 PCI card quite cheaply if USB is essential.

[sft42]

I agree with Buttons....USB isn't functional until windows boots up so there is no real reason why having a USB peripheral plugged in or not would affect the BIOS operation...Having said all that if it did work beforehand and not now then it would seem to suggest an XP problem....I only have XP home version so perhaps someone might be able to suggest something that is more familiar with the grown up version?

[dodgyshirt]

It could be an IRQ conflict.Also your claim to have`rebuilt an elderly computer' worries me somewhat. How elderly was it, did you upgrade any components such as the motherboard and RAM, if not did the motherboard BIOS need upgrading to accept XP, have you got enough RAM fitted (XP really needs a minimum of 256mb to run properly and preferably more). If you have upgraded are there any known compatability problems between the various items of hardware. Did you clear the BIOS after the rebuild and then ensure that USB was enabled in the BIOS.In fact the PC might be struggling to boot and the addition of USB peripherals could be the proverbial straw....If this is the case another PCI card is the last thing you want to be installing until your problems are sorted. Incidentally a `more superior USB 2.0' card is only of any use if you are using USB 2.0 devices.

[wrighty1980]

Thanks everyone for your insights. Dodgyshirt - your IRQ theory sounds interesting, how can I tell if this is the problem? In answer to your othe questions, I bought some more memory for it, but otherwise left it well alone! It is a P2, so its not too ancient, and otherwise is performing quite well. Might it be that it is trying to find boot instructions on one of the USB devices?

[dodgyshirt]

Go to Start/programmes/accessories/system tools/system information. Clicking on this will open up a window called System Information.Under System summary open up the Hardware Resources and check all the items under each heading. A similar check under the components section might also be interesting.