Just a little question...
I !BOUGHT! 3DGamestudio Commercial edition on the official site, get the download link, and downloaded the program. I installed it, but there was nothing written that it's the commercial edition. How can i know that it's THIS edition?

Open WED > Help > About WED... It will tell you your edition.

You also need to put your *.key file which you should have received somehow (per eMail for example) in the GStudio7 folder (where all the .exe files are)
Otherwise your installed version is just a trial version and expires after 30 days.

THX, I've got it.