Bios Mods -The Best BIOS Update and Modification Source

I currently have a bios for my dell with a stuck asset tag. usually this can be wiped from the bios though the bios is not allowing me to do this any more..
All that i need is for the textbox containing the asset to to be set to enabled so i can then update the tag(its set to disabled when it detects a tag)

any help would be appreciated!