ESXi 5.0/5.1 does not support Windows server 2012 R2/Windows 8.1 : (

1. The ESXi 5.0 doesn't support Windows server 2012 R2, you will see the error screen when boot up with the installation ISO image:

"Your PC ran into a problem and needs to restart. We're just collecting some error info, and then we'll restart for you."
This error will also appear in other certain situation, e.g. improper shutdown, restart,or some system files are deleted.But this time is another case, the OS version is not supported in current ESXi version. :(

 

 2. And you will not found find Win2012 R2 in  OS version when create a VM as it is not on the office support list,the Compatibility Guide shows that the ESXi5 requires at least Update  to run Win2012 R2(the requirement also apply for Wndows 8.1)
  
3. download the esxi5.0 offline update bundle from the vmware support site(sure u will need an vmware account) The esxcli software vib usage detail is here

# esxcli software vib update -d "/vmfs/volumes/51e5245e-45f7c8c0-bdc0-6c3be50dafb0/ISO/update-from-esxi5.0-5.0_update03.zip" 

4. Installation Result:

Message: The update completed successfully, but the system needs to be rebooted for the changes to be effective.

Reboot Required: true

 VIBs Installed: VMware_bootbank_ehci-ehci-hcd_1.0-3vmw.500.1.11.623860, VMware_bootbank_esx-base_5.0.0-3.41.1311175, VMware_bootbank_esx-tboot_5.0.0-2.26.914586, VMware_bootbank_ipmi-ipmi-si-drv_39.1-4vmw.500.2.26.914586, VMware_bootbank_misc-drivers_5.0.0-3.41.1311175, VMware_bootbank_net-be2net_4.0.88.0-1vmw.500.0.7.515841, ....

5. The update process needs a reboot, you will see the new added OS version in the Create  after reboot  

6.  For the Lab Workstation, Hp z420 is freezing on  when initializing ACPI after reboot , and the similar issue has been discussed in the communities .

I have figured out quickly it is BIOS related issue as another z420 Workstation with higher BIOS version, had no issue for the patch update. so we need to update the BIOS  firmware to the latest as well.

To update the BIOS firmware of HP workstation, first download the latest firmware from the HP support site . HP provide several ways to update the BIOS and i use  “Flash System ROM” feature.

• Download the firmware package and extract it in a Windows P
• copy the BIN file located at C:\SWSETUP\SP63328\DOS Flash\J61_XXX.BIN to USB.
• Boot the workstation ,use Computer setup (F10) and then select the “Flash System ROM” feature, the BIN file will be detected. 

7. Note above steps are for win2012 R2 Guest OS on ESXi5.0, it also apply for ESXi5.1 and Windows 8.1 Guest OS.