Acrobat X - device limit reached. Old pc died so I can't deactivate that copy

@ronald_2938 Oh wow, Acrobat X came out in 2010, and end of support ended in 2015; that's 10 years ago. Which means, Support, updates, and security patches officially ended. I wouldn't dare use this just because of the 'security' reasons. 

The reason you are getting the "device limit error" despite a dead hard drive is likely compounded by the fact that the activation servers for Acrobat X have been retired by Adobe. So instead, you think you deactivated the license, but because the servers are in 'limbo,'  the software is still licensed to that "dead" machine in Adobe's old database, hitting your two-device limit. Because the activation servers are retired, Adobe's customer support agents cannot simply reset the activation count on a non-subscription product like Acrobat X. Even if they could, the new installation would likely fail to connect for activation anyway on any new OS such as Windows 11. 

You could get a three year license of Acrobat, it's only good for three years, and once that three year is up, it stops working (non-renewing). This version is desktop-only and does not include the cloud services like mobile apps, file storage, or the newer Acrobat AI Assistant and PDF Spaces features. It's designed for users who need a powerful, offline PDF tool without the monthly commitment. Or buy a subscription to Acrobat. And if you are just doing viewing, printing, and sharing PDFs, maybe you can with the FREE version and get by with just Reader version only