start your machine.
press f8
choose safe mode
go to start,control panel,users,delete password
restart machine..done
mm, November 2008
I have no intention of telling you how to unlock a PC on an open forum and I hope that no one else will either as it is a recipe for increasing the number of stolen PCs.
Take your PC to a computer shop with proof of ownership and ID and they may be able to unlock it for you.