hdrscope uses temporary files rather than directly modifying the source .hdr files.
In order to achieve this, the software uses a cache storage under the system %TEMP% path. Every time a file is loaded in the software, a copy is made under this cache folder and all operations are performed using the temporary picture files.
Note: The location of the cache directory is by default set as %TEMP%. This can be changed from the Tools > Settings dialog box. Please note that since Radiance does not recognize space characters in the path, if your %TEMP% contains spaces (for eg. if your user name in the computer contains spaces), the software will fail to execute commands that utilize Radiance binaries.
All the settings parameters from Tools > Settings menu are by default sourced from the settings.asf file which is stored under %APPDATA%\hdrscope. This file _SHOULD_NOT_ be moved to other locations, edited or deleted. User preferences can be set from Tools > Settings.