Can someone plz tell me if I download pmdg 737ngx can I install it on two computers or do I have to pay separately

Yeah you can install it on both.

Yeah you can install it on both.

Sort of but you must read the EULA.

 

This is from the PMDG 737NGX readme located in C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\PMDG\PMDG 737 NGX

 

1. GRANT OF NON-EXCLUSIVE, LIMITED LICENSE

The Software and related documentation is licensed, not sold. Any rights not clearly and expressly granted to you under this EULA are reserved to PMDG. Provided you have paid all applicable fees, registered the Software with PMDG, and otherwise complied with this EULA, PMDG Simulations grants you the following personal, non-exclusive, non-transferable, limited rights:

 

a) One user may use the Software on the Customer's computer where the software was installed; you may use the Software on a second computer so long as only one copy is used at a time and only after having secured a second license permission from PMDG.