Can't activate, Error Code 0c8007007B

Been wrestling with this for a few days.

This is an upgrade. Did a custom install from XP Pro 32-bit to Win 7 Pro 64-bit.

Well, I have tried it a few times actually. I have tried all the different methods for the custom install, including upgrading the upgrade.

The error code description is:

"The filename, directory name, or volume label syntax is incorrect."

I get this when I try to activate, before I'm prompted to enter a key code or anything.

I have verified the OS is genuine with the online tool.
I have installed all drivers and updates, and it's SP1.

I have had so much trouble moving various new hardware from XP32 to Win 7 64.... the past 10 days I seem to have had more trouble than I have had in the prior 10 years.

This one is specific to this computer. I have another activation error of a different sort on another machine but I'll get to that later

All fixed. This turned out to be an error caused because the default client is KMS. I switched the key to MAK and all is well. And I larned me a couple things

Seriously though, since this did not come up on a google, if anyone else finds this here is a quick explanation:

When you download an OS from the VLSC, by default it comes with a KMS key pre-installed. This is so you only have to activate one machine on your network, which then activates all the other clients.

If your organization is smaller like ours, you probably just want to use the MAK keys, which are one-time activations for each computer. To do this you simply follow the directions here:
Converting KMS Clients to MAK Activation