Suddenly can only delete or backspace one letter

classic control panel: open the control panel. Go to keyboard. Skip to Changing the settings______________ | Category view(default from XP and up): | Printers and other hardware | scroll down and click Keyboard | | Changing the settings V Move both the Repeat delay and Repeat rate bars about 2/3 the way up, or until you like the result. Test in the provided text box. Click apply, then OK. You are done!