Lingvosoft provides Bengali translation software for Windows. You can download trial versions, to see what works best for you. The software packages fall into these basic categories:

• Bengali Talking Dictionary (just under $50). This is what most people are looking for. Load this on your machine, and you have a virtual translation device. It delivers instant bi-directional translation of all the words and phrases in its massive database.
  

•  Bengali Phrasebooks (just under $50). Have the power of 14,000 travel-oriented phrases at your fingertips! You can instantly translate in either direction, too. This software features advanced speech recognition and crystal-clear output of native-speaker voice narration.

• Bengali Flashcards (just under $40). These make studying and foreign language as easy and enjoyable as it should be. Featuring 5 enjoyable games that make learning fun, they are the most effective way to memorize thousands of new words. Just install this program on your computer, and you can begin  developing your command of a second language in record time. The  customizable interface allows you to choose from numerous options to make the experience the most comfortable possible.  

• Bengali Software Bundles (prices vary, depending on the bundle). A software bundle can provide significant cost-savings, if you need multiple languages or you want to combine the features of other offerings into a single economical package.