Product Tab
Step 1 - Go to Customer Master - Product tab 
Step 2 - Select Activated 
Step 3 - Select AMC Due Date
Step 4 - Select Installation Date
Step 5 - Click Edit 
Step 6 - Click Save
Step 7 - Go to Customer Master - Product tab 
Step 8 - Select Active
Step 9 - Select AMC Due Date
Step 10 - Select Installation Date
Step 11 - Click Edit 
Step 12 - Click Save
--- After Save Event - Select Check Box Auto Selected 
--- In Both Above Conditions - All Fuctionality Working With Edit Mode and Select Check Box Selection