You can change the limit of PDFs to be opened in the Read&Write via the ReadAndWrite.exe.config file:
1. Ensure Read&Write is closed.
2. Go to C:\Program Files (x86)\Texthelp\Read And Write 12
3. Open the ReadAndWrite.exe.config file using NotePad.
4. Locate the line:-
add key="MaxPDFWindows" value="3"
5. Change this to:-
add key="MaxPDFWindows" value="4" (or whatever value is required)
6. Save the file
This should only be done for an exam and the limit should only be increased up to the maximum needed (eg 4 or 5), as there can be significant performance impact when using PDF Reader with many files.
Please note: The new config file can be deployed to multiple machines.