Thank you for writing to us!
Unfortunately you will not be able to change the service tag to the system at any given point in time.
Kindly private message the service tag and email address.
Install the software first
Go to C:\program files\Dell\Command Configure
If 64 bit OS go to x86_64
If 32bit go to x86
Go to sub dir HAPI enter hapiinstall.bat
This will install the software to control\Access the BIOS
then go back one dir
type cctk --asset then the asset name
IE CCTK --asset=12345678