I played with my Raspberry Pi B+ for a while. Then while upgrading the OS, it crashed. So I decided to re-install the OS from scratch and document it during the process. Here it is.
First step is to get a MicroSD card. I would suggest minimum 8GB. Insert it an SD card adapter and insert it in a card reader of PC. Install the SD Formatter application on your PC and run it as Administrator. (Right click the application in windows start menu and select “Run as Administrator”). Click options and set “Format type” to FULL and the “Format Size adjustment” to ON. This will make maximum disk space available for use. Format the card after making sure that the drive selected in the formatter tool is indeed your SD card’s.
Next, download the latest RASPBIAN image from the Raspberry Pi site. I used the RASPBIAN JESSIE image. Follow the instructions on that page to install it on the SD card. See the installation guide link on that page for the instructions. You must use a special image writer tool to write the image. Link to the tool is in the installation guide.