Blacklist a Computer
Blacklisting a computer deactivates Parallels Desktop on it and makes re-activation using the same license key impossible. To re-active Parallels Desktop on a blacklisted computer, the user will need to use a different license key. You (the administrator) can remove the computer from the blacklist at any time, in which case the same license key can be used again.
To blacklist a computer, in the main computer list, select one or more computers (select a checkbox in the first column), then click the Actions drop-down menu and choose Add to Blacklist.
To view the list of blacklisted computers, in the main computer list, click the Computers drop-down menu and choose Blacklisted.
To remove one or more computers from the blacklist, select the computer(s) and click Actions > Remove from Blacklist.