1. Create a new SSH key. Here we call it id_rsa, which is the default, but you can give it any name you want.
ssh-keygen %HOMEPATH%/.ssh/id_rsa
2. Use PuTTYgen to create a private PuTTY key id_rsa.ppk, from id_rsa.
%HOMEPATH%/.ssh/id_rsa.ppk
3. Create a new BitBucket account.
4. Click on the Manage Account button on the top right.
5. Click on SSH keys on the left, then on the Add key button.
6. Copy the contents of id_rsa.ppk and paste it into the Add SSH key dialog.
7. Clone the Git repo with TortoiseGit using the PuTTY key id_rsa.ppk.