Just install QT, no need to uninstall PRE9.
I would second nealeh's reply, but in addition....
Just some miscellaneous, just in case, notes...
If you have Premiere Elements 9, please check that you are running it as the 9.0.1 Update.
The latest version of QuickTime that you installed comes as a 32 bit version and is used
in your Windows 7 64 bit.
Could you clarify
I just downloaded Quicktime 7 (I have Windows 7 64bit).
Do I need to uninstall PrE9 before installing Quicktime
What were you using for your Premiere Elements 9 before this current download of QuickTime since Premiere Elements requires installation of QuickTime on the same computer as Premiere Elements in order for Premiere Elements to function properly, especially for QuickTime exports?