My laptop works fine only when I continuously press and hold any key on the keyboard

Bizar problem: My laptop works fine only when I continuously press and hold any key on the keyboard.
Laptop type: Fujitu-Siemens Amilo M 1420
OS: Windows XP SP2
If I (re)boot the laptop it always freezes in the “XP startup screen”. When I press any key on the keyboard, hold it, the booting continues… When I lift my finger and release the key I was holding, the booting stops, press down any or same key on the keyboard again and the booting continues, when booting complete, the touchpad and keyboard will not work, when I again press and hold any key I can use the touchpad and type/use the keyboard… to be short my laptop works perfect if I press and hold (doesn’t have to be hard, even when pressed very GENTLY) any key on the keyboard… which makes this a VERY bizar problem.
The motherboard got renewed in warrantee time and ?fixed? the problem for about a month or so after that the same problem occured but outside warrantee time!
From visiting the Fujitsu-Siemens website/forum I know that there is at least one more user of the exact same laptop that has the same problem.
I’m very interested/curious on what you will have to say about this and by all means very much obliged for it.
Thank you.
Dirk

You are right, it’s very bizar. May be it’s some kind of new security future from Microsoft, so nobody can control your laptop remotely? Just kidding.
I think it could be a software related problem. You can test the laptop with a live Linux CD – the operating system that runs directly from the CD. I usually use Knoppix, you can download an image and burn it on a CD. After that start the laptop from the CD and wait until the laptop boots to the desktop. See if the problem still exists. If the laptop boots fine and all keys work properly with Knoppix but not with Windows, you have a software related issue. Reload Windows.
Or just reload the operating system without testing with Linux. I think it might help. Do you remember if the operating system was reloaded after Fujitsu-Siemens technician replaced the motherboard? May be the motherboard wasn’t your problem last time?
If reloading the OS will not help, the next step would be removing the keyboard. Disconnect the keyboard from the motherboard and start the laptop. If the problem is gone, probably you have a bad keyboard.
If the problem still exists even after the OS is reloaded and keyboard removed, I would say you have a bad motherboard. I don’t know what else could be wrong.

Just a few days ago I had to repair a laptop with kind of similar problem. The customer complained that her keyboard doesn’t work in Windows, but she still can type here password at the login screen. I started the laptop and typed the password without any problem, but as soon as laptop booted to the desktop all keyboard keys stopped working. I reloaded the operating system and it fixed the keyboard problem.