You have to install QT 7 from the Snow Leopard disk. Here are Apple's instructions:
To install the QuickTime Player 7 from the Mac OS X v10.6 Snow Leopard install DVD:
Insert your Mac OS X 10.6 Snow Leopard Install DVD.
Open the Optional Installs folder and double-click "Optional Installs.mpkg".
Select the QuickTime 7 option and click Continue.
QuickTime Player 7 will be installed in your Utilities folder.