Pro Tools 5.1.3 and 5.2 each contain unique features. Pro Tools 5.2 provides DigiStudio online collaboration capabilities, while Pro Tools 5.1.3 has enhancements for AVoption|XL, MediaManager, DigiTranslator, and Avid Unity(tm) MediaNet users. Both Pro Tools 5.1.3 and 5.2can reside on the same hard drive, but cannot be launched at the same time.To install 5.1.3 and 5.2 on the same hard drive:Run the installation disk on a machine currently installed with the other version.In this case, running the installation disk will not disrupt the previously installed version.Both versions will be added to the Pro Tools application folder (with version numbers clearly stated) within the Digidesign folder. If both versions of Pro Tools are installed on your hard drive, you should not open a session by double-clicking on it (you will not be able to choose which version of Pro Tools you want to work with).To open a session when both versions (5.1.3 and 5.2) are present:Launch the Pro Tools version that contains the features you intend to use, then open thesession through the file menu. Or just drag and drop your session onto the icon of the desired version.If you open and save a Pro Tools 5.2 session in Pro Tools 5.1.3:You will lose the Local > Online track associations.If you open a Pro Tools 5.1.3 session in Pro Tools 5.2:You will loose the ability to work with the DigiTranslator option, MediaNet storage and 24P video clips.You will be unable to play audio imbedded in an OMFI sequence file.Pull-downs will only be allowed at the standard frame rates.Pro Tools AVoption and AVoption|XL users:You will have the full capabilities of your video system while using Pro Tools 5.2 online with DigiStudio,with the exception of 24P support.