I have a dell inspiron 5100 with service tag # 7WGV731. I was having problem with my computer and uninstalled the operating system. While the operating system was removed I had a new motherboard put in the computer. When I know turn on the computer it comes up with a black screen and blue box that says, "Enter Password (Service Num:3544831). I have no idea how to get rid of this and I can't do anything on the computer because of this. When I try to type things in if i get it wrong to many times it says "system disabled". Any help is greatly appreciated.