windows - ffmpeg drawtext initialization error

I'm trying to convert an image sequence to a video file with some text overlay(eventually frame counter).

The command I am using

ffmpeg -r 24 -y -i mambo_%05d.png -i ..\3DW_Mambo.wav \
  -vf drawtext="fontfile=/Windows/Fonts/arial.ttf:text='test' " test.mp4

Unfortunately everytime I try running it, it can't seem to find the font. I've seen other people succesfully use the same syntax, so not sure what I might be doing different?

I've checked that the font is named correctly.

Answer

Carl suggests double escaping

-vf drawtext="fontfile=C\\:/Windows/Fonts/arial.ttf:text='test'"