Fujitsu seimens s series life book

my laptop was working normally, suddenly i realized that key board has stop working properly, it is only typing x all the time to the infinity. even it is working automatically in bios setup, change the values itself, etc.... i tried to reinstall the windows but i cant give product key....because it was xxxxxxxxxxxx .......my system time and date in bios hasbeen changed automatically as well.......plz help me to resolve it.