Hi

What you do depends on why you reinstalled, the version of the software and the message you are getting.

If this is a clean installation and the message you are getting is saying you have exceed the allowed number of activations then you need to contact Magix to get the activation counter reset, explain why you need it resetting.

If this is MEP2015 or VPX 6 and it is saying you cannot change the registered computer then you must unregister the other computer if available, failing that contact Magix to get the old installation deregistered

If the registration process cannot connect to the Internet then check any firewall settings to see if the program is being blocked.

However - if you re-installed because of a problem with MEP then it is highly likely you will not have fixed the problem.

Remnants and settings from the program are left behind by the uninstaller.  If this is the case then you should uninstall again then run the Magix Cleaner available here (page 2) before re-installing the software.

HTH

John