Right-click on any QVD row to show the context menu. Select "Select for Compare" to mark the first QVD for the compare. The selected row will be highlighted. 

Right-click a second QVD and select "Compare with Selected" to launch the Compare process.

Metadata from both QVDs will be displayed and differences highlighted.

•Comparison may be made between tabs.
 

•To deselect a QVD marked for compare, right-click the QVD again and select "Compare with Selected"/

QViewer version 4.3.1