Capcom has confirmed the release date for Dead Rising 3 PC version as September 5.
Take a look at the official announcement tweet below:
We are also happy to confirm Dead Rising 3 PC's release date for September 5th. Yay!
— Capcom-Unity (@Capcom_Unity) June 19, 2014
For PC System requirements go here.
Related: Dead Rising 3 Announcement Trailer
Source: Capcom Unity