Error Touch Input (please, help!) "The application touchh Input has stopped unexpectedly" :(


I have an HTC Desire already for a couple of years, and today every 3 seconds I get the message booting up that saids:
The application Touch Input (process has stopped unexpectedly. Please try again."
Button: Force close

So I click force close. Then every few seconds it pops up again the same message.

The touch screen seems to work fine, but the message still appears frequently and it is impossible to bring up a keyboard (it looks like a keyboard doesn't exist anymore,). I cannot write anything (e-mail, sms, whatsap