I have limited space on my C drive which is an SSD hard drive… how do I tell Scrivener to store all my project folders on my other hard drive by default… is there an option for this?
Scrivener remembers where you last created a project, so the next time you create one, create it where you want it and subsequent new projects to go. You can also close Scrivener and move your existing projects to the other location.
You might consider visiting Tools->Options->Backup and changing the location of the automatic backups (and you should move the existing backups to your new location).