You could have QV9 and QV11 desktop versions running at the same time.
Follow these steps
It is not possible to have multiple versions of QlikView Desktop installed, i.e. the QlikView 11 Desktop installer will overwrite a QlikView 10 Desktop installation. However, the QlikView 11 Desktop executable file can be copied to any location on the hard drive and run from there without conflicting with the installed QlikView version. In order to run multiple versions of QlikView Desktop on a single machine, please follow this procedure:
a) Uninstall prior version
b) Install QlikView Desktop v11
c) Copy the QV.exe file to a new, safe location
d) Uninstall QlikView Desktop v11
e) Install prior version
Following this procedure, you end up with a working version 11 QV.exe, but the operating system treats the prior version as your primary version of QlikView.