Keyboard isn't working in Boot Menu (even reformatted)

Is it a usb keyboard or does it have a ps2 plug ?

http://en.wikipedia.org/wiki/PS/2_connector

If you reformatted the hard drive and the problem persisted afterward then that might remove the OS and hard drive from the equation.

One thing that occurs to me: If this actually was a result of a viral attack then it might ber a better test to wipe the hard drive (zeroing out the entire drive) prior to re-installation. Formatting will prepare the drive for OS install and look clean, but there can still be data there, particularly in the first sectors.
You may need to use a program like Partition Wizard from a bootable CD to do this job, since using Windows Diskpart as we normally would may not work due to the lack of keyboard control.

Another thing to check is in the BIOS/UEFI. You could check to see if the USB settings are correct, but it might be faster and easier to reset the BIOS defaults. (Be sure to note all the current settings first so you can change them back).
If that doesn't do it then try a ClearCMOS procedure. This will re-initiate all the hardware in the BIOS and may clear up any PS/2 or USB problem

If you need instructions on doing any of these things, just ask.

AddRAM said:

Is it a usb keyboard or does it have a ps2 plug ?

PS/2 connector - Wikipedia, the free encyclopedia

The keyboard is USB. but when this happens, I've switch to PS2 but still not working.

TVeblen said:

If you reformatted the hard drive and the problem persisted afterward then that might remove the OS and hard drive from the equation.

One thing that occurs to me: If this actually was a result of a viral attack then it might ber a better test to wipe the hard drive (zeroing out the entire drive) prior to re-installation. Formatting will prepare the drive for OS install and look clean, but there can still be data there, particularly in the first sectors.
You may need to use a program like Partition Wizard from a bootable CD to do this job, since using Windows Diskpart as we normally would may not work due to the lack of keyboard control.

Another thing to check is in the BIOS/UEFI. You could check to see if the USB settings are correct, but it might be faster and easier to reset the BIOS defaults. (Be sure to note all the current settings first so you can change them back).
If that doesn't do it then try a ClearCMOS procedure. This will re-initiate all the hardware in the BIOS and may clear up any PS/2 or USB problem

If you need instructions on doing any of these things, just ask.

Thanks for the tip. I haven't tried to reset BIOS settings so I'll try tonight. But even I cleared cmos by switching the jumper and removed cmos battery, still nothing, but I'll try that again.

It's not on virus' fault, but something in hardware or BIOS settings.

Doing a ClearCMOS automatically resets the BIOS defaults. So that's been done.

To be clear: the keyboard works fine on another PC with Windows, it works fine in BIOS, and it works fine in Ubuntu, just not in Windows - even in the pre-desktop environment, correct?

Check the BIOS settings for USB settings. You can toggle the setting for Legacy USB Support on and off to see if that changes anything.

Then see if you can boot into Safe Mode to see if the keyboard works there.

So now the keyboard will not work in BIOS? How about Ubuntu?
What is the brand and model of keyboard? USB or PS2?

When you get to the screen where it says press any key to boot from CD, that is the BIOS. The BIOS does not hand off to the OS until a boot device has been started.

There can be two "boot menus" depending on the machine and who's talking.
The first is BIOS/UEFI based and can be accessed by pressing ESC (usually) just as the PC starts up but before the system hands off to the OS. Here you can choose which drive you want to boot from.
The second is a Windows based menu that you get to by pressing F8 just after the BIOS finishes it's routine but before the OS starts loading. Here you can choose which mode you want Windows to start up in.

Both of these menus require you to press a keyboard key to activate them. So my question is when you say "cannot use keyboard in boot menu", how are you getting into the boot menu? Or are you saying that the keyboard works until you get into the BIOS boot menu but once there it stops working?