This may seem a little odd - does the right click work OK in other programs eg Windows Explorer?
I can think of no reason why the right click does not work in MEP, except that the mouse is faulty or the windows settings for the mouse are incorrect.
Re-installing without running the Magix cleaner tool does not always work in correcting problems.
Try using Windows Explorer to search your c: drive for videodeluxe.ini - you will have to search hidden and system folders as well - you should find several of them, one of them will be a larger file size possibly in the range 12 - 20kb whichever is the largest, delete or rename it then start MEP.