From the File menu in VSP, you can choose the "Password Protect VSP..." option so that anyone opening the software is required to enter a password.  This helps make sure no accidents are made to the database, and that only those who should see the database on that computer, are able to do so.

However, only the one machine the password is created on will require the password.  For example, if VSP is installed on four different machines, and you choose the option to password protect VSP on one of those machines, no other computers on your subscription will be asked for the password, only the actual computer the password was setup on.