Identify duplicates of two columns combined

Problem statement - There are multiple departments and a particular software can be used in more than one department. In this case S1 is being used by Dept A and Dept B. I need to identify such softwares. I can't use the inbuilt duplicate function because that will also highlight S1 version B also being used. Also it will highlight S3 as it's different versions are being used by the same department Dept B. So in this case it should just highlight S1 as it is being used by 2 different departments. The requirement is to find the same software being used by more than 1 department. Have tried Vlookup but no luck.[ATTACH]855598[/ATTACH