Please read the release note from here
Installation instructions for current users:
Current version uses a new installer which supports both 32 bit and 64 bit (on a 64 bit environment) version to be installed simultaneously. As such any prior version have to be uninstalled before installing the new version.
- Close any open instances of ArthaChitra.
- Goto Start > Control Panel > Program > Uninstall a program
- Select "ArthaChitra 1" and click on Uninstall
- Download and install the new version from here