You can install Serum 2 on up to 4 different machines.

If you need to deactivate Serum 2 on a machine you are no longer using, you can do so on your Xfer Records account page: xferrecords.com/my_account

Locate the machine (listed by Machine ID) then delete the one you no longer need to free up activations.

If you need assistance in handling the number of authorized machines, you must contact Xfer for support: support.xferrecords.com