How to Activate a licence more than 30 days after installation

My 80 year-old dad installed eM Client in mid-January and requested and received a free licence (he recently upgraded to Windows 8 from Vista and could not transition to the new Windows Mail app. eM Client classic view is a lot more like what he is used to). He has been using it for a month and likes it a lot, however on the 31st day following installation it will no longer open on his computer. I suspect he did not install his licence activation key properly back when he received it. Problem is, he cannot open the application to activate/install the licence key and confirm that this is the problem, even though it remains installed on his computer. Is there a way to do this, or does he have to uninstall and re-install the software? If a re-install is required, does it need to be uninstalled first (or will it re-install over top of the current installation and preserve his settings, contacts, sync to gmail, etc.), and will his original licence key remain valid?

Hi, could you please specify “no longer open on his computer.” Does he see any error message?

Reinstall (full with manual deletion database and then pure installation with activation) will solve this, but I think this could be possible to solve without this not so standard way how to solve things.

If he has not activated his license then it will be valid, if he did and eM Client was not “deactivated” then it will be problem.
Fastest way would be to register new free license on another email.

So if you will decide to reinstall follow these steps

  1. uninstall eM Client
  2. delete database folder “eM Client” in C:\Users\ current user \AppData\Roaming\
    (you will need to turn on "show hidden folders in Windows)
  3. Install eM Client again, add account and activate.

please be aware of that step 2 will delete any not synchronized or backed up data.