Problem: Upgrading 32 to 64 bit server on VMWARE ESX 4.x would result in a stop when booting the Windows 2008 x64 CD

Error Message: STOP: 0x0000005D (0x000000000FEBBBFF,0x0000000000000000, 0x0000000000000000,0x0000000000000000)

Resolution: Obvious one really, change the Architecture to be (64 BIT) for the VMWARE properties of the VM