Thanks for your prompt reply! This helps me realize maybe I didn't download the right installation file.
It was Magix_Vegas_Pro.16.0.0.261_multilinguAL_X64.ZIP, but this was not the file recommended by the seller. I'll try again acc. to seller's directions , and I'll let you know how if this solves the problem !

So... I downloaded and installed the file recommended by the seller (actually the install file vegamoviestudio16_dlm.exe from MAGIX site) and... same problem. I'll need a computerID to activate the product. I hope you can help,

You should be able to "activate and register downloaded programs using your serial number after installing them on your computer". You need to check with the seller that they have given you a valid serial number.

Thanks, but still the MAGIX site requests an "ComputerID" for activating the program. How to get this Computer ID ?

@John-CH Usually the installation picks this up automatically from your pc system. Strange that it isn't for you.

Anyway my pc ID is what appears in Windows Settings/System/About. The "Device Name" under "Device Specifications" is what gets used.

I have installed and registered several versions of Vegas Pro and Movie Studio, and the Computer ID has always been assigned on the first activation. It is not something you "fill in." Of course, it your product has already been registered, it will look for a certain "Computer ID," and you must de-activate it in your Magix Account before it will accept a new activation.

But as far as the Computer ID being a blank box on first registration, that is entirely normal and expected. So don't let it's absence cause you to race your engine.

Hello friends,Thank you to all of you for swiftly addressing my problem. I think I made a mess installing different files one upon the other. So I thouroughly cleaned up my computer (Windows registry included) of anything looking or smelling like Sony Vegas, and reinstalled the file provided by my seller. And lo and behold, it worked ! Vegas Movie Studio 16 is now installed, activated and running ! Now I can put my precious Vegas editor to work again, my favorite among all modestly priced video editors (even the newest ones) ! Thanks again for trying to help me. I think you did!

... or smelling like Sony Vegas

I am glad that you have worked the problem out, but you seem to have failed to realise that Vegas Pro is NOT a Sony product despite being advised of this in the first comment after your original post.

... or smelling like Sony Vegas

I am glad that you have worked the problem out, but you seem to have failed to realise that Vegas Pro is NOT a Sony product despite being advised of this in the first comment after your original post.

Thank you Dexcon for the heads up ! I must get used to this fact and will comply. Although it's not quite correct to state that VEGAS is not a Sony product. It would be more correct to state "is NO LONGER a Sony product, since Sony has been the developer and the version 16 is not much different from my Sony Vegas purchased 10 years ago. Actually Movie Studio 16 still SMELLS A LOT like Sony Vegas as the word "Sony" appears in more than 100 files names belonging to Vegas 16 ;-)

Please note that it is quite incorrect to use "Sony Vegas" when you are referring to the versions later than #13. As the pinned post states, "the VEGAS Team advises that they want to avoid the appearance of misusing a brand that isn't theirs". Sony sold MAGIX the rights to the Vegas name as well as the software in mid-2016.

Thank you for considering this.