As of Project Reality v0.9, the Project Reality Team are using passworded installers. This is so we can release the installer early, and "unlock" it at the official release time. This way, everyone can start playing as soon as possible after release! All you need to do is use the following passwords with the appropriate version, and the install will continue as normal.
Project Reality: ARMA 2
Project Reality: BF2
Select the password you require and press Control+C to copy the password. Then select the password field in the
Project Reality installer and press Control+V to paste the password.