If you copy these two directories: (including subdirectories)
%Appdata%\roaming\j river\media center 26
Program files\j river\media center 26
And do a library backup on the old pc, and restore with settings on the new pc, that should get it done.
It won't be "first time" because you will have to do a library restore, as I said. And if you're doing a new install one the new pc, you will have to activate/register MC.