Ok ive bought and downloaded Episodes from liberty city from steam but i have the normal gta4 on a disk because i just recently started to use steam, so when i tryed to run i got the rmn40 error (even know im on vista) and i googled on how to fix it but it sayed to go to properties in the GTAIV launcher.exe but thats not in my steamapps folder because i own the game on disk. Is there anyway to put my GTA4 onto steam so that i can change the compatibility mode or somhow bypass this error?