Please capitalize where necessary: if your pc opens the d83 file, but it's the wrong application, you'll need to change your windows registry file association settings. in other words, windows is associating d83 file extensions with the wrong software program.
A: If your PC opens the D83 file, but it's the wrong application, you'll need to change your Windows registry file association settings. In other words, Windows is associating D83 file extensions with the wrong software program.

Please capitalize where necessary: resist waves of zombies with your car! buy new cars, upgrade your engine, tires or armor. ...
A: Resist waves of zombies with your car! Buy new cars, upgrade your engine, tires or armor. ...

Please capitalize where necessary: in 1673 he was appointed count with the name griffenfeld, and the year after he became chancellor, as such the highest ranking official in the kingdom.
A: In 1673 he was appointed Count with the name Griffenfeld, and the year after he became Chancellor, as such the highest ranking official in the Kingdom.

Please capitalize where necessary: 1973: first international connections to arpanet: norsar in norway and the university college of london. the connection went via satellite.
A:
1973: First international connections to ARPANET: NORSAR in Norway and the University College of London. The connection went via satellite.