keyboard acting strange

Suddenly,today,my keyboard is unusable (i’m typing this question with the ON-SCREEN KEYBOARD)because no matter what i try (a different keyboard;loading new keybd software or drivers;system restore;or even a clean reinstall of Windows XP)when i hit any key, something erratic and strange types onto the designated program (it’s the same with all programs!)
For example, when i hit the keys for ‘keyboard acting strange,’ this is what results: “k,ceyfbvo.lard a,ctimng xstramnge.”

I run win xp pro; Intel pentium4 3.06 Ghz system; 1 gig DDRAM PC2700 333mhz memory; 140 gig 7200rpm Maxtor hd; one dvd drive and one cd rewriter/reader drive.