My idea is childish But HUBMeister says go to Microsoft Windows and try to download say updates or microsoft antispyware ,The microsoft site will check if u got original cd key or not!!I know guys windows acivation crack is famous on net
How is anyone supposed to know if ur key is valid or not if you dont provide more info ( key itself ) . only microsoft can say if ur key is original or not IF you bought cd urself and got key with it then it must be original . If you got it with ur computer or from friend or someone then its pir*ted . Above method is best if u really want to know ur key is valid or not .