I already have Trados Studio 2007 on my computer and when I installed SDL Trados Studio 2009 I wanted to have both versions available for use because one of my customers has not upgraded to 2009 yet. I thought I had selected the option to have both versions running side by side but 2009 has "taken over" the computer. If I re-install 2007 what must I do to ensure both versions are running? ( I could also run one version on my laptop).