I only tested this to work on Dell Inspiron 660 and Inspiron 3847. Note: I am not responsible if you try this on another PC and brick it. Important: You must download a new copy of the BIOS (full size ROM) from Dell Support website! This has a larger size (8 MB) instead of the ~3.5 MB file you will get if you just dumped your BIOS using AFUWIN/AFUDOS/AFUEFI/AFULNX! This will allow you to program in a new service tag (as a side effect of reprogramming the entire flash ROM). You can also enable the hidden advanced menus using the procedures at the following post: https://forums.mydigitallife.net/th...-advanced-menu-unlock-bonus-msr-unlock.54523/. This procedure worked on both computers I tested. Note: I only tested this to work when I had modified the BIOS file already by enabling the hidden advanced menus. If it does not work for you, you may have to first modify the BIOS file to enable the hidden menus before flashing it. You can make a backup of your current BIOS by using "AFUWINx64.EXE BACKUP.ROM /O". 1. First run the downloaded flasher file so that it extracts the ROM file to a temporary directory. DO NOT CLICK ANYTHING IN THE FLASHER WINDOW. 2. Press WIN+R, type "%LOCALAPPDATA%\TEMP\" and press enter. 3. Sort the opened window by date modified and copy the folder with the name of the executable file to a directory of your choice. You may now close the flasher window. 4. Open an elevated command prompt window and navigate to the new directory. 5. Close all other windows. Then, run "AFUWINx64.EXE [ROMFILE.ROM] /GAN" where ROMFILE.ROM represents the name of the 8 MB ROM file (MSK-A13.BIN for Inspiron 660's latest BIOS). The flasher will now flash all blocks. 6. Optional: Run "FWUpdLcl.exe -f [MEFW.BIN]" to upgrade the Intel ME firmware (note: I did this after step 7). The file is named 1416upd.bin for Inspiron 660's latest BIOS. 7. Restart your computer and press F2 to enter setup and change service tag. You may then need to load default values or reconfigure boot settings to allow the computer to boot into the OS.