I notice you're looking for a download of "Proshika Shabda" for Windows 10. However, I don't have any verified or safe sources for that specific software. It's possible that:
Smart Writing Tools: Includes a built-in Bangla spell checker and grammar checker to ensure your writing is error-free.
Because Proshika Shabda was developed in 1994, it is a legacy application. To use it on Windows 10:
Downloading and installing Proshika Shabda on Windows 10 is a journey back in time. It requires patience, a 32-bit version of Microsoft Office, and a willingness to tweak compatibility settings. But for millions of Bengali writers, it is worth the effort.
: It offers a layout that many long-time Bengali typists find more intuitive than the standard "Bijoy" or "Avro" layouts. Lightweight Design