I'm trying to update the BIOS on Lenovo ThinkCentre M58p which shows a BIOS date of 05/07/2012. When I boot from CD with the iso file it asks whether I want to update the serial number and model type. After that it begins the procedure of updating and everything seems like it well. But after saying that the update was successful and restarting into BIOS, no new settings appear and the BIOS date remains the same. Upon trying to boot from CD the second time however, after the serial and model questions I'm warned that BIOS on the CD is a lower version or the same as the BIOS installed. Even after the second try it all remains the same.
Version 5CKT77A, dated 05/07/2012, is the latest version of the BIOS. Lenovo updated the release date on their download page http://support.lenovo.com/us/en/downloads/ds013586 from 5/16/2012 to 6/2/2015, but without changing any of the actual files. You can verify this by looking at old snapshots of the page on the Wayback Machine at archive.org.