Using ASP.NET, whenever I write to a file, I've had to set permissions on the file level.

For example, the other day, I was saving to an XML file, and I was getting the usually permission error, which went away after I set permissions for the NETWORK SERVICE process on it. (VS.NET 2003). I noticed that setting permissions on the containing folder had no effect.

My question is, what if I want to create a new file? Will I need to set permissions on the folder itself, or what?

Any info on permissions will be helpful.