Okay guys here's my problem, I recently just purchased The Sims 3 for PC/MAC from bestbuy.com who does a partnership with the company digitalriver.com. I chose the option to directly download the game after purchase from its website. Unfortunately the download program uses a .exe file called "Sims3_DownloadManager.exe" which of course is a PC file. So it downloads all the required files and does this automated installation afterwards. I have installed the Sims 3 game fine on my PC; but when I try to copy the installation files on my portable hard drive or DVD disc and try to install it on my MAC via the .app installation folder on the game. I get an error stating the following, "can not verify the integrity of the installer". The window closes after that error message. Any help would be greatly appreciated thank you.