I have got many files which are created in Quark Express 8.5. I need to open up those files either in Quark Express 7.5 version which is already installed on my machine or I need a plugin to open it up in In Design CS5.
Only Quark 4 files can be opened directly in InDesign without any 3rd Party software. So unless you can save all the way back to Quark 4. Then you will need the plugin from Markzware.