Start with scans with free software Grif notes at http://forums.cnet.com/5208-6142_102-0.html?messageID=3105025
This just started happening last week. When I type in some applications, I get a random string of characters. For example, when I type the same character ("t") in Word, I was getting this string of characters: "5467890-=mqwertyuiopasdfghjkl;?`\zxcvbn", which looks suspiciously like the order of keys across the keyboard. I'm seeing this problem in Word, Excel, iTunes, and some browser form fields, but not in the URL field of FireFox, or in the DOS prompt, for example.
I just bought a new keyboard (Logitech wireless) in case it's a hardware problem with the Dell original keyboard, and it's still happening even with the new keyboard. When I reboot, everything starts working fine again, until I go away for a while and come back. I'm running Vista Home Premium with SP 1 on a Dell DX061. The only changes I've made recently are re-installing Zone Alarm and adding a HP wireless networking card. Any thoughts?