How can i get the path of the current user's "Application Data" folder?
Look at combining Environment.GetFolderPath and Environment.SpecialFolder to do this.
Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)
Depending on what you are doing you might also want to look at
Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)
If the user is on a domain it will only be stored in their local AppData
folder and not synced with their roaming profile.
Have a look at the Environment.SpecialFolders
Environment.SpecialFolder.ApplicationData;
Environment.SpecialFolder.System
that should get you round the username requirement as well.