[grabby]

I recently changed a PC's license key for Windows 7 pro from a personal key to a Volume License key because the key on it was obtained from msdn. I did this because it was a school only computer so it deserved the Volume key. Would this have any tie to the Volume License key coming up as an invalid key?

[cluberti]

If you need to change a retail or OEM product key to a MAK or KMS key, you should be using slmgr to uninstall the old key, remove traces of it from the registry, then install the new MAK or KMS key. If you use the Computer Management UI, yes, this can happen.

slmgr /dlv   - this helps you find the activation ID for the current activation; run this with the old retail or OEM key installed
slmgr /upk <activation ID>   - this removes the current product key by removing the activation ID
slmgr /cpky   - this removes the product key from the registry
slmgr /ipk <product key>   - this adds the new product key
slmgr /dlv   - this will show you the new activation ID for the newly installed product key
slmgr /ato <activation ID>   - this will activate the new product key

Once you've done that and rebooted, you should no longer be told it's an invalid key. If you're still getting "invalid product key", check to make sure it's not a KMS key and your machine can't contact the KMS server, or that it's not a MAK key that has no remaining activations (either of these scenarios can cause "invalid product key" warnings for MAK or KMS keys, especially KMS server activations).

[grabby]

Thank you for the post, sorry for taking so long to respond, I haven't quite got it working yet. I'll let you know how it turns out.