Inspirion 1501 Service Tag wrong

I'm working on a friends Inspirion 1501. I replaced the motherboard and now the service tag does not match the PC and they do not have the CD's that came with the PC. I have tried serveral utilities but all are failing to update the service tag in the BIOS and it will not allow me to manually update it. Please help.

asset.com ver 2.02
This machine does not support an asset/service tag

svctag
erase service tag Y/N  Y
I told you what I am. But what are you?
EE-CPB.exe: Error 0

asset tag utility ver 3.4
working buffer size provision failed. Error code 86