I have a Compaq laptop running Windows Vista and was bought in 2008. Recently, the keyboard stopped working after booting. (Once the loggin page came up it wouldn't respond) At first, both the keyboard and touchpad were not responding, but after running a scan, the touchpad started working. I bought a wireless USB keyboard to see if that would work, and it did not. I have ran a start up check, bought new virus software, reinstalled the keyboard as well as upgraded and downgraded it. I'm not sure if it's a virus, software, or hardware problem.
Boot to the vista dvd and see if the keyboard is stable. 1/3 of highway deaths are caused by drunks. The rest are by people who can't drive any better than a drunk.
I sadly do not have the Vista CD.
Do you have an friend that has a bootable cd or dvd? You just want to see if you can replicate the issue, you don't want to boot to any install menu. Keyboards usually interact with menus by the tab key so that should be test enough. If nothing else, get and burn a cd from linux like a live linux. Ubuntu, OpenSuse, Fedora, Mint, Gentoo and many many others have great live cd's to be used for a test.
I would prefer you test with a MS disk.
1/3 of highway deaths are caused by drunks. The rest are by people who can't drive any better than a drunk.