Hi.

System: Win XP Pro w/SP2.

The problem:

With a wireless USB KB and Mouse connected, the machine refuses to boot.
The machine will POST, but then the screen goes black - you do not even get the Windows XP splash-screen during boot-up.

The BIOS directly supports USB KB and Mouse, so there should not even be the need for drivers.

With a standard PS/2 KB and mouse connected, the machine boots just fine.

If I plug in the wireless USB KB and mouse after the system has booted, I can use these too, however, XP flatly refuses to boot, if the PS/2 KB and mouse, are not plugged in.

It does not matter which PS/2 device - they both have to be plugged in, or the machine won't boot; IE: If I leave the mouse in, but the KB out, XP won't boot. If I leave the KB in, but the mouse out, XP won't boot. If I leave both the PS/2 KB and mouse in, XP boots fine.

While in the system when it was running, I installed the drivers that came with the wireless KB and mouse anyway, and rebooted.

Exactly the same problem; IE: XP refuses to boot, if BOTH PS/2 devices are not plugged in.

If I have both PS/2 devices AND the wireless USB KB and mouse plugged in, XP refuses to boot also.

THE ONLY WAY I have found so far to make the wireless KB and mouse work, is to plug in the wireless USB KB and mouse after the system has finished booting - I can't even leave the bloody thing connected at startup, or XP refuses to boot.

What the @%^@! is going on here?!!?!??!!

Any ideas?

What does your BIOS have to say about this? You may need to enable usb keyboard and mouse.

Also look for a setting in the BIOS regarding enabling Legacy USB support.

BIOS is already set to:

USB Keyboard Support: [Enabled]
USB Mouse Support: [Enabled]

This is the default setting, and they are already enabled.

*sigh*

Could there be a halt on keyboard or halt on all errors setting in the BIOS that you could try tweaking with or even this "think-keyboard-plugged (http://www.mp3car.com/vbulletin/faq-emporium/62621-faq-fooling-pc-think-keyboard-plugged.html).

I'VE FIXED IT!!!

As an experiment, I went into the BIOS, and changed the USB KB and Mouse support to [Disabled].

That done, XP boots fine, sees and uses the wireless KB and Mouse.
:)
:)
:)

Ahhh, technology - sometimes it tries us...
(actually, more frequent then I would like, most of the time!)

Paul: BIOS was set to Halt on: [No Errors], meaning it should keep going, even if there was a KB or mouse error..

Anyhoo, it seems to me, that what was happening, was that the USB KB and mouse was being used at BIOS level, and then along comes XP, and tries to load drivers for the PS/2 KB and mouse, along with generic drivers for a USB KB and mouse - the drivers hit each other in RAM, and crash the boot-up proceedure.

My opinion only - would love to hear the real reason.

Well done. Strange one but I guess you are right about there being some sort of conflict (IRQ ??) at the BIOS level. That was a reason for mentioning legacy support (http://www.intel.com/support/peripherals/sb/cs-011939.htm) (when it is an option) since there is both legacy and more advanced USB support. USB Mice and Keyboards coming under the spread of HID (Human Interface Device) (http://en.wikipedia.org/wiki/USB_human_interface_device_class) classes.

There is also a longer MS page on USB Boot Support (http://www.microsoft.com/whdc/archive/usbcompat.mspx).

mjc has also often pointed out that the USB bits loading always follow all the other stuff done during startup - thought this is more pertinent to loading things for windows than for halting the POST altogether.