Installing 5.0 after having tried the trial version

I have Mac OS X 10.7.5 and I installed the trial version of Parallels 8.0 to try it out. Unfortunately, I don't have the money to upgrade right now, so I'm temporarily going back to the most recent version I have which is parallels desktop 5.0. I uninstalled 8.0 using the uninstall feature. But now that I'm trying to install it, after downloading it, it gives me an error saying "Parallels Desktop can be installed only on Mac OS X Leopard (version 10.5.2 or higher) or Mac OS X Tiger (version 10.4.11 or higher)."

I assume the issue is occurring because of my previous install of 8.0, but I'm not sure. Obviously, Lion is greater than Leopard.... Any suggestions on how to fix this?

Thanks

 

No, the problem occurs because PDM5 is not compatible with OS X 10.7. The error says exactly that, it only runs on 10.4 and 10.5.
There is no fix. Only PDM7 and 8 work on 10.7.