Encoreviewer 2.1 and Encoreviewer 2.0

I was using Encoreviewer 2.0 converted from 32 bit to 64 bit on my old PR system machine.
I bought a new Series 60 PR machine which requires Encoreviewer 2.1 and it will not install correctly on my computer and It says I need to install the Microsoft NET framework configuration tool and opens to a blank viewer screen.
The software works fine on my girlfriend's computer which did not have any previous verisons installed.
Anyone else have this problem?

I finally figured out what the issue was and I'll pass along the information for anyone that has a converted 32 bit to 64 bit older version Encoreviewer 2.0 and wants to install 2.1.
I had to go into windows Explorer and delete all 2.0 programs and files from my C drive.
I selected the C drive and did a search using 2 keywords. encore and respironics searching each word separately.
I had to run 3 passes using each word to completely get rid of everything.
Don't forget to reboot your computer before installing Encoreviewer 2.1.