You do not need a license to run MVPspc. When unregistered, the full features of the product are available, except you cannot copy or print, and you will see the words "unregistered copy" in small text on the graphs. When you purchase a license and register, these limitations will be removed.
If you are upgrading, and wish to find out what changes have been made see What's New in MVPspc.
When upgrading, this installation program will replace your existing MVPspc program with the latest version, keeping your license information and settings intact.
Note: if this program fails to upgrade your version, you will need to uninstall the prior version and download a new version.