Converting .pem file to .ppk to use in Putty(Windows) or vice versa

If you ever face a situation like, you have .pem file that is used in linux and some of your colleague wants the .ppk file to use in Putty (Windows) to connect to Linux host.

You can convert the file via below steps:

Install the putty tools, if you don`t have on Linux:

sudo apt-get install putty-tools

Now you can convert it to pem via below command:

puttygen key.pem -O private -o key.ppk

-o Tells it where to write out the converted putty private key
-O private Tells it that you want a putty private key

Now you have key.ppk that can be used in Putty (Windows)