Locked your dell inspiron 1545 forgot password what do you do?

It depends on which passWord you forgot. If it's that one for BiOS, you have to send it to DELL and ask them to cancel the passWord. They charge for such things so get ready you credit card. If you forget passWord for Windows then again it depends on which kind of Windows you have. For vista ultimate with BitLocker on there is no chance to cancel passWord. You will have reinstall system or cancel the passWord and loose all data on encrypted drives. You have something simpler, you can find a special CD in internet to cancel passWords for Windows NT based systems (Windows NT, 2000, xp, Vista Home, Business and so, Ultimate with BitLocker off).