change the Maximum number of PDF files that can be opened concurrently

[bhphoto]

I would appreciate if anyone can give me some info in Acrobat how to change the Maximum number of PDF files that can be opened concurrently.

The default is 1000 in version 4.05 and up but it doesn’t work properly only with 20 files at once.

Your help is very much appreciated.

Thanks
JoelB

 

[bhphoto]

Sorry, I made a big asking my question and I will rephrase it:

Adobe claims that Acrobat should be able to open 1000 files concurrently but in fact when we try tpo open we can only open 20 and when opening the 21th it will close another one.

Sorry and thanks
JoelB