If there is a few people out there who have the Steam version of Mafia then you have probably had an issue with trying to get the game launch. All you get is a white screen and then an error message to press an OK button to close the game. Well I have heard there was a patch out there and I didn't really do to much searching around but I did find one. This patch however is no longer available cause the link that once hosted the patch seems to be broken. So there is another fix and its as simple as changing the compatibility settings
So lets begin!
(Click on screenshots to enlarge)
Step 1 locate where your game is by right clicking on your game in Steam and going to properties
Step 2 go to the local files tab and click Browse Local Files...
Step 3 a new window will open you'll want to right click on the game icon and go to properties
Step 4 go to the compatibility tab and set to Windows XP SP3 and Disable display scaling on high DPI settings. Then press OK.
Step 5 Open the game and now you should be able to play. Do note that Steam overlay will not work with compatibility settings. If you want to take a snapshot of the game use Geforce Experience or use the Windows key + Prt Scrn. Check out the following screenshots from using this fix.
(NOTE) THE GAME IS KNOWN TO CRASH A LOT