Honestly, unless you are only going to dabble, you don't want your data folders on your c:/, they get huge. I'm at the point I have over 2 TB of content. Fortunately you don't need to put it there. The DIM and Daz Studio both need to be on your C:/, none of the content does though. If you are using the Download Installation Manager you can set both the download directory and the install path to be on any drive you want. Then you need to Point Daz Studio to the same place. Keep in mind if you use an external drive, 1) it has to be connected when you are using DAZ Studio (comes under the heading of "No Duh") but also those things spin down when not in use, and they some times take some time to spin back up again. This can cause delays when you first access your library after a period of doing something else. It's minor but it can be irritating at times.