I followed this
tutorial to downgrade my steam GTA IV 1.7 to 1.4
I've used this tut once before and it did work, but now Steam, Rockstar, or the GTA IV.exe will not start the game and get an error.
I tried 3 times so far and the same thing happens.
Apparently one of the downloads from the tutorial didn't download correctly.
I grabbed downloads from a youtube video and now the downgrade works.