I think that's it :/
VMware Player 4.0 - Source : VMware Player 4 Release Notes
Installation Requirements
When you install Workstation, the installer performs checks to make sure the host system has a processor that meets the following requirements. You cannot install Workstation if the host system does not meet these requirements.
- 64-bit x86 CPU
- LAHF/SAHF support in long mode
You can use CPU-Z or a similar utility to determine if the host system CPU is 64-bit capable. CPU-Z shows EM64T (Intel) or AMD64 (AMD) if the processor is 64-bit capable.
If you plan to install a 64-bit guest operating system in a virtual machine, the host system must have one of the following processors. Workstation will not allow you to install a 64-bit guest operating system if the host system does not have one of these processors.
- AMD CPU that has segment-limit support in long mode.
- Intel CPU that has VT-x support. VT-x support must be enabled in the host system BIOS. The BIOS settings that must be enabled for VT-x support vary depending on the system vendor. See VMware KB article 1003944 for information on how to determine if VT-x support is enabled.