I had this system before, i have installed Windows 2008 64 bit and even Windows 7 64 bit recently without any problem.
Have you tried to install the OS on its own? I mean without using the VMware.
I did install VMware ESXi v3.5 long time ago, still i did not encounter any problem.
Try without VMware as a test and see if at least a normal windows installation works or not.
I dont know this VMware Vsphere v4, it sounds interesting, i will try it next time.
The cpu that you are using does support 64 bit OS.
It is worth trying the new BIOS and firmware update:
All the best,
We were selecting the proper OS when installing through VMware.
I am unable to upgrade the BIOS & FW. Intel should provide this as a bootable ISO instead of pointing customers to a 3rd party web site on how to create a bootable usb drive. After following the directions I still had no luck. I've given up on this so no need for responses on how to resolve this issue.
My original issue has been resolved "can't install 64-bit OS on S5000psl". Originally after enabling VT option in the BIOS I did NOT power the system off, just used the BIOS option F10 to save changes and reboot. Apparently you have to physically turn off the system and back on for this change to take full effect. We can install Windows 2008 64-bit edition now. Thanks for the responses.