On Windows, default terminal for Atom\'s Platformio-Ide-Terminal is Powershell (at least, that is what I get without any configuration).
I would prefer a terminal using
Step by Step Solution
Put the following line as per as your Terminal Requirement
For cmd- C:\\WINDOWS\\System32\\cmd.exe
For Power Shell- C:\\WINDOWS\\Sysnative\\WndowsPowerShell\\v1.0\\powershell.exe
For bash- C:\\Program Files\\Git\\bin\\bash.exe
or C:\\Windows\\System32\\bash.exe
(depending on how you install the bash). Be Sure, that you have already install the bash into your computer.
Now, you can integrate bash, cmd, git bash, Power Shell into Atom using platformio as terminal.