Hi, today I installed eM for testing purposes… and because I am a idiot, I entere my free key (after 10 minutes of program run). Is possible to switch to the trial again? I need test multi account function before buy and with my free key I cannot 
Try go to Help -> License -> Deactivate and see if you still got the trial period left.
I am tried this, but now I am in the limited functionality mode (offline only)… I am tried resintal too…
Trial period is short - 14 days only. If you passed 14 days, there’s nothing you can do. You can install it on another PC for another 14 day trial.
I wrote at the begining:
“Hi, today I installed eM” and “after 10 minutes of program run”
Oops, miss that. Give me a break dude, I’m still on holiday. Try to delete the database:
C:\Users%Current User%\AppData\Roaming\eM Client (Vista/Win7)
C:\Documents and Settings%Current User%\Application Data\eM Client (XP)
If still no go, I’m out of ideas.
No problem 
a try this when I come back to the home…