Ryzen 5 1400 2 cores disabled

Solution
Have you changed anything on 'System Configuration'?
If you did then go back to 'BOOT Advance Options' and uncheck 'Number of processors' and 'Maximum memory'. Reboot.
If that's not the issue then make sure to have the latest BIOS for your motherboard.
Have you changed anything on 'System Configuration'?
If you did then go back to 'BOOT Advance Options' and uncheck 'Number of processors' and 'Maximum memory'. Reboot.
If that's not the issue then make sure to have the latest BIOS for your motherboard.
 
Solution