What I'm looking for is not to simply change the whole userdata to another drive, but to create separate drives for each users, and have their application data, my doc, etc folders on their own drives.

Sadly, from looking at environment variables though I think it's not possible.. What do you think ?

My goal is to manage drive space in logical partitions. For example, I don't want to have the whole userdata directly on D: 's root, since nothing would prevent anyone from creating D:/new_folder for example..

Any idea ?