VMWare Workstation 8 reporting “”vmx86 driver version invalid handle” problem on booting VM

Guessing Lock files were left. Remove .lck files that pertain to your vm. Same directory as the .vmdk for the VM you're trying to use.

edit: I no longer believe that my response, below, is useful. I would encourage others to provide alternative answers.

Running 64-bit guests on 32-bit hosts is a dodgy affair to begin with. Surprisingly, VMware Workstation apparently can accomplish this under limited circumstances, but I think you would be much better off with a 64-bit host OS.

Here's what I would recommend:

1. P2V your existing 32-bit Gentoo host and make sure that it boots in VMware Workstation. Depending on whether you use fixed IP addressing or can foresee other potential conflicts, you may want to be careful about virtual network adapter settings for the purposes of this test.

2. Make a backup everything on the box, including your new Gentoo virtual machine.

3. Slick it and install any fully supported 64-bit host OS.

4. Launch your existing 32-bit box in a VM. Of course, you can run it in full screen mode, give it a bridged network adapter, and use it as your "primary" operating system. If you have enough RAM and give it a physical disk of its own, you shouldn't notice any significant change in performance.

5. Run 32-bit and 64-bit guest operating systems to your heart's content.

There may be reasons why this wouldn't be possible for you, but if you have no blocking issues, it could give you a fully supported path forward.