AVG Notifications Erased But Also Deleted an Unrelated Needed Program

Opening a PDF triggered a trojan warning from AVG Free.  I opted to secure the trojan.  It also showed several notifications that were at risk.  Afterward, I tried to open a often used program for group mailing called e-Campaign.  Suddenly the computer could not locate the icon to open the program.  In looking at the notifications that AVG recommended I erase, several of those were connected to the e-Campaign program that had nothing to do with the trojan alert (was for a PDF document received from someone else, and opening on Gmail.),

I need to get my e-Campaign program back in working order.  What can I do, please?  Many thanks for any help.