recording in mono but want to in stereo

[SANKE_]

so i have recently recorded a small youtube video and only after i had finished recording i see that my microphone was only recording in mono and i want it in stereo how do i do it.
im using a condenser microphone

 

[Alabalcho]

You can't make "stereo" signal out of single-channel recording. You'll need special microphone (actually, two of them) to make good stereo recording.

How did you make that "mono" recording - both channels have same signal, or only one channel has it, with other channel muted?