Well, if you have a really good Internet connection, then the easiest way is to download SBUU (Systems Build and Update Utility) and SUU (Server Update Utility) ... boot to SBUU, choose Update Firmware, then insert the SUU DVD (must be dual-layer DVD or USB) when prompted for the repository. You could also install Server 2008 (which only takes 15 minutes), then update each individually from Windows.
Hi,  I am planning to install ESXi 5.1 and I would like to upgrade the BIOS from 1.5.4 to the latest one. Others have suggested that I should upgrade any other firmware from the system (bmc and drac). I checked Dell Drivers website and I downloaded the BIOS. I am trying to figure out how to upgrade the bios on a PowerEdge 2070. I burn a cd but that did not work, I also tried using a bootable USB (using Unbetbootin) it recognizes it but nothing happens. Does anyone have a better idea/suggestions on how to upgrade the BIOS and the other hardware firmware?  Thank you.  
PowerEdge 2970 - Bios upgrade help