Quicken will not open

My Quicken program (app) will not open. The problem started last week. I've had the group from WebRoot and Microsoft both review the situation seperately; after subsequent time on line in my PC both stated all systems were operable but I still can not open my Quicken account. Today on a whim I attempted to open my Turbo Tax programs and they also could be open. I haven't tried Quicken support directly yet, thought I would try this site before to seee if other users wee having similar problems.