Step1. Download Avro Keyboard Software From http://www.download.com/Avro-Keyboa
Step2. Install Avro Keyboard. If you are able to write using Bijoy, OR not! No Problem Use Phonetic Option. Avro is a unicode font. So you can write every website in bangla and also send mail to your relatives using this software.
Step3. Download Font Fixer using this link http://www.omicronlab.com/tools/fon
After install both Softwares, you must Restart your computer.
Thanks.