Sound Forge, Vegas and most other Magix software can be activated on two (2) PCs simultaneously. If it is needed on a third PC, one of the original two will need to be deactivated. There are two ways to deactivate, visit the MAGIX Service Center and log into your account, go to "My Products > Show More Details > Deactivate". This option can only be used once a month.
.. However an alternate deactivation method can be used as often as you wish. From SF's 'Help' menu, choose 'Deactivate the Software on this PC'. The PC must be connected to the internet,

A Sound Forge 365 subscription can only be activated on one PC at a time.