I can't find my downloaded files or settings. Where are they?

Windows Vista and later versions have a new "feature" called Data Redirection which is a security feature provided by a driver for the file system and registry which will redirect writes targeted at certain protected locations, such as %ProgramFiles%, from its original location to the actual user’s profile. In other words it prevents write access of protected locations if a program running in user mode.

When in local mode (portable, zip archive download) DC++ stores its downloads and settings in the program folder where it has been unpacked. If you use the default settings and run DC++ with different userlevels you may unable to find your downloaded files where you expect them or experience various errors during saving and accessing downloaded files if you unpack the portable version to a Windows system folder.
E.g. when you unpack it to Porgram files then the default settings the downloads directory is:
"C:\Program Files\DC++\Downloads"
But in a situation described above it could point to the following virtual place:
"C:\Users\[username]\AppData\Local\Virtual Store\Program Files\DC++\Downloads"

To avoid this try one of the following :
- run DC++ always as the same user/level (user or admin)
- never unpack DC++ under the 'Program files' or other system folders
- set your downloads AND(!) unfinished downloads directory outside the 'Program files' folder (it can be set in Settings/Downloads panel in DC++). You may want to refer the built-in help topic for Unfinished Downloads folder setting as well. It mentions an easy way to reduce the possibility of running out of disk space during downloads.
- set a different folder for your settings, etc.. files and default downloads using the dcppboot.xml config file which can be found besides the DC++ executable.
- disable User Access Control (UAC). This will stop the Data Redirection service as well (not recommended).