Windows 7 - Keyboard freezes at Windows 7 login screen if a key is depressed

Hi all,

I have an Acer Aspire 5517 notebook with a very strange problem. The keyboard and touchpad work fine until I try and type in the first letter of my password, then both freeze. If I don't touch the keyboard once the login screen appears (by using the Ease of Access on screen keyboard), I can use the touchpad for as long as I want. But touch one of the 101 keys - pfft, they both lock up. My power key is set to Shut Down, and I can always use that.

A few other things: if I let the laptop charge for awhile while it is turned off, the keyboard will work normally. If I reboot it after a few minutes after that, the keyboard will once again cease to work. When the keyboard won't (or doesn't) work, there will be no listing for keyboards in the Device Manager and under keyboards in the Control Panel there is no driver listed for it, that tab is just blank. No errors in the Device Manager either. When the KB does work, everything is listed normally in both Device Manager and the Control Panel.

After looking around this forum and others, I've tried a few things: in-place Windows re-install, then an Acer full re-install, then a full install using an MS Windows 7 disc. Always the same result. Some said it was a dying battery, so I went and bought a new one, same results. I also installed ubuntu, thinking the problem wouldn't exist there, but sure enough, it does.

How a keyboard always works before loading an OS, or after letting it sit charging while turned off, and then not work the rest of the time has got me terribly confused.

Sorry for the long post, but if anybody has any ideas, I'll try anything.

Thanks all.