Some readers of the instructions for converting a Parallels VM to Fusion
http://www.vmware.com/pdf/fusion_vm_from_parallels.pdf
have complained that it needs a concluding chapter. Because Parallels VMs running Windows are built using a non-ACPI HAL, and because converting a VM from Parallels to Fusion does not change the HAL, converted VMs cannot use Fusion's support for dual virtual CPUs.
The solution is to change the HAL. Before Windows XP, it was fairly easy: just go into Device Manager and choose a new one (NT4) or delete the old one and reboot (2000). And the point is moot for Windows Vista: VMware Converter does not yet support converting Vista installs. But Converter does support converting XP installs, so a lot of people have been using it to bring their Parallels XP VMs to Fusion. Unfortunately, Microsoft does not support changing an XP VM's HAL without reinstalling Windows.
A lot of people asked, "Okay, how do you do that?" So I prepared this followup. If you follow it, be sure to make a backup before you start! The following is one guy's experience, not an official VMware document. Frankly, most of what's in this document is Microsoft stuff rather than VMware stuff anyway.
I started off with a Parallels VM and converted it to Fusion using the instructions in the PDF I linked to above. I even installed VMware Tools in it. As you will see later, I could have omitted that step, but I wanted to mirror what most folks will have done with their converted VMs up to this point.
Next I connected my VM to a Windows XP SP2 CD. When Windows noticed the CD, it ran the CD's autoplay script and gave me this menu:
I picked "Install Windows", chose Upgrade from the "Installation Type" pulldown. I had to re-enter my Windows product key. Pretty soon, Windows rebooted into its text (non-GUI) installer.
WARNING! If you're following along with me, be alert here! When Windows reboots, click once in the window to ensure that it has input focus. Windows will, for a few seconds, display a message telling you to press F6 if you have a driver disk. Instead, when you see that message, press F5.
Windows will not acknowledge the fact that you pressed F5 right away. But in a few seconds, it will show you this screen:
Believe it or not, that's a scrolling window. Use the up-arrow to scroll all the way up to ACPI Multiprocessor HAL or ACPI Uniprocessor HAL.
Either of these HALs will allow your VM to shut down cleanly, without requiring the gui.exitonCLIHLT = "TRUE" .vmx file hack that that PDF discusses. But only ACPI Multiprocessor HAL will allow your VM to have two virtual CPUs. So I picked ACPI Multiprocessor HAL and let the reinstallation proceed.
Eventually Windows rebooted into its GUI installer, and the boring part began.
After 30 minutes or so, Windows finished reinstalling itself; I declined the opportunity to register my copy of Windows again; and then I had my VM back. Just one catch: the mouse was a little broken. Apparently, something in the reinstall process messes up the VMware mouse driver. So I hit ctrl-cmd to get input focus out of the VM, and then re-launched the VMware Tools installation once again (as always, by pulling down the Virtual Machine menu and choosing Install VMware Tools).
But this time I did a Repair of VMware Tools rather than an Install.
I allowed VMware Tools to reboot the VM as always, and my mouse was back to normal on reboot. Next I wanted to take advantage of the fruits of my labors! So I shut down the VM.
Look! Stand By isn't grayed out anymore! That's because we now have an ACPI HAL.
While the VM was off, I went into Fusion's Settings dialogue and changed the number of virtual CPUs from 1 to 2. Then I booted up and reveled in the multiprocessor goodness.
Mission accomplished.
