I am about to upgrade from Movie Studio 8d Platinum to Movie Studio 9 Platinum Pro Pack. Should I delete the old version first or install over the top.
Not sure about Vegas Studio EULA since I did not read it, but in the past when I wasted time reading the EULA's, many of them required removal of the previous version as the upgrade's license was suppose to REPLACE the previous version's license, that is why price was discounted. In other words, having the previous version, then purchasing an upgrade did not give you licenses to use both concurrently, legally you had a license only for the one installed, previous version or new version but not for both. Remember, you are not buying the software, you are buying the license to use the software.
With all that said, I would recommend a close reading of the EULA when you install the upgrade to see if such restrictions are present.
Past experience with other software.
I kept the previous version just in case there was a compatibility issue with my old project's features or plugins not working in VMS9 I can still run them in VMS7.