Need to place user uploaded aspx file in asp.net application

In my asp.net application, users can upload / download files and ASPX files are accessed by the user later (it must implement security at the code level, because it would be better to use the application with minimal permissions to run). So now I have to save these files and where is the best place to store them. Should I give permission to record low in the current project to create or should I create a separate like "www.mydomain.com/files" and up virtual directory. I also want to prevent restarting the application domain. What is the best option to deal with this situation?
