Laptop asking for weird password

[golfinguy5]

So my motherboard recently fried but just before it did I uninstalled windows xp. I had the mother board replaced while there was no operating system installed. When i now turn on my computer it comes up with a black screen and says "Enter Password (Service Bum:3544831 )" I've tried everything I know and have called dell and they cant figure it out. I have a dell inspiron 5100. Any thoughts?