To renew a existing installation you can use a command promt and type "md1752_en_x64.exe /s" /s triggers silent install so it doesn't ask to retype keys. Only works for active installations with working keys. If you just run the install normally you'll need new keys. If you allready installed Mdaemon on your PC that doesn't work anymore. Install it on a new PC, request keys and abort that installation. Use the key on your own server.. You could use a virtual machine too, prepare the VM so it only needs a fresh install to work properly and install Mdaemon. When the trail is over, restart your VM so it's a fresh install again and install Mdaemon again with a new trail key.