RE: Optiplex 9010 Intel Management Engine BIOS Extension (MEBx) option disappears after selecting from BIOS.
Thanks Robert. It looks like it was a matter of BIOS being pretty old. In fact I noted the BIOS revision as A14, It as A05! So I updated it to A24 (latest for 9010s of this kind). In fact I updated all the BIOSs in the lab to A24 for 9010s and A17 for 9020s. All works fine now.