How do you convert Mono to Stereo?

How do you convert Mono to Stereo?

is it a possibility?

cause i have a Mono tape which i recorded onto DVD, which i assume has now two channels both the Mono effect. correct me if im wrong.

and then basically, i was ought to extract the sountrack from the DVD and find a way how to get it into somewhat a true Stereo sound.

may i ask if anyone here might know how to do this? i also dont know if i am saynig this in the right place.

i would really appreciate it if anyone can help me.

also, i like to know, since the tape was in Mono, and i assume this is the reason why the volume is sooo low. when i turn the volume up pretty high, i can hear a light fan sound effect wen the people speak and so on. does anyone know if this occurs in all Mono tapes? or is this a one of a kind situation? also is there a way to fix this or know what is this effect happening?

im sorry if i said too much, hehehehe, i would really appreicate it.

thanks very much.