Hi Roel, Good to see that the UPS shutdown software is working well.  In order for the server to automatically restart following a UPS shutdown event you just need to set the server BIOS status to "always on".  It sounds like you have it set to "last known state" or similar right now.  When you set the BIOS to "always on" the server will sense when the UPS turns back on (because there will be power applied to the server power supply) and it will automatically turn on. Hope this helps. Andy
Hello, Been struggling with this for a while with reseller, but their answer is, "not possible". Which I don't want to accept... We have several sites with: Dell UPS Rack/Tower 2700W Dell R710 with ESX4 / ESXi 4.1 the UPS and ESX are configured nicely, when a poweroutage occurs after 15 minutes the VM's are brought down and finally the server is shut down. My issue is with power restoration. When the power is restored we can't get the ESX server to boot. We are lead to believe that it is not possible to have the ESX server booted because the server was shutdown with a shutdown command, therefor it will not automatically boot upon power restoration. Can someone please help me out with this as I can't accept that it is not possible to automatically boot the ESX server after power restoration. Thank you for your comments! Regards, Roel 
Dell UPS Rack/Tower 2700W and a R710 ESX 4.0 / ESXi 4.1 environment