I had a computer with CS6 Design Std and Acrobat X Pro that was recently reformatted. I have the license keys for both. When I log into my account, I have CS6 listed but not X Pro. When I try to register the license with this account it says the license is in use, but I don't know what account it is registered under if not this one. How do I find the original account this license was purchased with so I can migrate it to my current account?
you don't migrate anything. you install both with their installation files and activate with their serial numbers.
if you see an excess activation count error, that can be fixed in your account or with the help if adobe support.
Hi @HCS32673304wd3z when you reformatted the activation did not go away on the Adobe server. So it still thinks that original license is in use. Contact Adobe Customer Care to deactivate the original registry and you can then activate.
Go to https://helpx.adobe.com/contact.html and log into the site. Click the chat pod on the bottom right and type AGENT to get a real person who can help. Be patient 1:1 customer care puts you in a queue. Or you can reach out on Twitter at AdobeCare
...and make sure to only ask to have your activations reset.
Sorry, I should have added some more context. The computer isn't mine as such, it belongs to a client I've taken over support for. They gave me the account ID that was used for CS6, but they only have the serial for X Pro and don't know what account it was purchased under since it was so long ago.
"an account id used for cs6" is too vague to be helpful.
but if they purchased from or registered with adobe, they can log into their account (with adobe id and password used at the time of purchase/registration) and access the installation files and serial number(s)
if they don't know the id/password and don't know their serial number(s) and don't have anything else to work with (eg, an activated installation somewhere), they're out of luck.
otoh, there are possible work-arounds if there's something to work with.