Laptop stops typing after a few letters

My son has a laptop - Fujitsu Amilo L7310GW (XP home), all of a sudden the keyboard and touch pad have started playing up.

The keyboard just stops typing after 6-12 letters, doesn't seem to matter if its word processing, notepad or browsing. If you close the application and re-open it you can type again but still just a few letters.

Also, if you have two or more windows open, it randomly minimizes windows by itself.

Is this likely to be a new keyboard\touch pad that is needed?
or maybe a USB keyboard and mouse would get it going, if so, is it possible to disable the laptop keyboard and touch pad?

Any help would be much appreciated - thanks

I would take it apart and check that the keyboard fitting is secure in the motherboard. Once inside there, get some compressed air and give it a good cleaning. Once secured, check it again. If still not working, hook up a USB keyboard until you get a replacement keyboard (cheap on ebay). You don't need to deactivate the laptop keyboard to use a USB one.

Ever spill any liquids onto the keyboard? Soda or beer can be especially damaging even when cleaned up and dried out.

Symptoms of mismatched power supplies include mis-charging batteries, battery not charging at all or beyond a certain point, power bricks overheating, inaccurate battery meters or charging indicators, unexpected shutdowns, reboots and more. I highly doubt that the only symptom you would notice is the keyboard, although it is certainly possible.