Num lock on IBM Model M keyboard must be cycled sometimes after startup

[Phormio]

I have a gray-label IBM Model M keyboard that I got used off of eBay.  When the computer starts up, I enter my Windows password using the numpad.  On a regular basis (though not every single time as I recall), the numlock light is on but the numlock doesn't work.  I have to press numlock key twice to get it to go off and then once more to get it to come back on again.  Then I can enter my passord using the numpad.  This is annoying.  Does anyone know why this is happening?

My guess is that I could solve this problem either by getting a PS/2 to USB adapter or by buying a Unicomp keyboard that has a USB cable.  Before I do either of these things, I thought I would ask you guys to see if anyone has any recommendations.

[Gatix]

Also check your BIOS settings. Some motherboards have a setting on what the numlock state should be on boot.

[Phormio]

Thanks!  I checked, and the BIOS was set to have numlock on at startup.  I turned it off, so now I need fewer keypresses to enter the Windows password.