HI @Frédéric Giguère ,
If you don't want to use Group Policies (GPO), then you could simply give the users temporary local administrator rights on their computer, and once the users are done with the installations, remove the local administrator rights, this can also be automated with scripts.
Similar discussion over here:
https://community.spiceworks.com/topic/99721-temporary-right-to-install-software
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(If the reply was helpful please don't forget to upvote or accept as answer, thank you)
Best regards,
Leon