If the board hangs on "Er", you may still be able to force BIOS recovery.
The string is a serial or manufacturing code often found on older Intel Desktop Boards , specifically those using the LGA 1150 and LGA 1155 sockets . While it is sometimes mistaken for a BIOS error sequence, it actually identifies specific hardware versions or batches for legacy boards used in systems from the Windows 7 era . Understanding the Hardware Identity Intel Desktop Board 21 B6 E1 E2 Er
ports (functionality depends on the installed processor's integrated graphics). Legacy Support If the board hangs on "Er", you may