Open the command window and change to the PTQ directory:

Type:
cd\program files\modartt\pianoteq 7 (or whereever you installed PTQ)

Now start the conversion via command:

For example type:
"Pianoteq 7" --preset "HB Steinway D Pop" --midi C:\MyMidiFiles --wav C:\MyMidiFiles

This converts all midifiles in C:\MyMidiFiles to WAV-format in the given directory with the Steinway Pop preset.
To convert the files to mp3, just change "--wav" to "--mp3".

There are even parameters for bitrate, normalization, dithering etc.

To see a full list of parameters type:
"Pianoteq 7" --help

Tip: If you do this often, write the commands into a batchfile. Like "MIDtoMP3.bat"

with my friend Google, I see that there is a lot of software making what you want. Audacity seems to do that very well.

Good luke !

I have got a bunch of midi files that I'd like to export/record in wav / mp3.  I use windows.  Can anyone point me out how I might be able to do that?