How to open two independent instances of Foxit Reader?

I'm trying to open two PDF files simultaneously, in order to compare their contents, one on the right (Win→) and another on the left (Win←) side of my screen.

Unfortunately I'm trying without success. I already tried to open another Foxit reader, using "open as", but nothing worked.

May I have to install Adobe and Foxit to do that?

There's an option in Foxit Reader's settings that allows multiple instances of the program to be opened.

Go to Tools->Preferences->Documents->Allow Multiple Instances

However in Foxit Reader version 7.2.2: go to Edit->Preferences->Documents->Allow Multiple Instances.

This will open single file in multiple windows not in multiple tabs. Then arrange windows vertically or horizontally to view two files simultaneously. However, I have not found the split window command like Adobe Reader in Foxit.

In Foxit Reader 6.0 this option is here:

File->Preferences->Documents->Allow Multiple Instances

In the others versions the useful funcations can be found here:

Edit->Preferences->Documents->Allow Multiple Instances