How can I keep Adobe Acrobat Reader DC from automatically installing in my PC every 2 hours

I own a Dell Latitude with Windows 7 SP1. I installed Adobe Acrobat Reader DC, but later replaced it with a paid version of another pdf converter. The issue is Adobe Acrobat Reader DC keeps automatically installing itself and marking itself as the default program to open pdfs every two hours. Every time I open a pdf and realize its been open with Reader DC, I uninstall the program through the Control Panel, and have even used the tool AdobeAcroCleaner_DC2015.exe to clean any registry entries that might be left behind, but still every two hours have to repeat this process again.