Thanks to BetterRed and Sirtel for their clarifying posts.
I know about Window associations pros and cons, but I didn't understand you were talking about it... my fault.
Regarding the Open With feature, I just discovere it after my 4.0.0. install and viewer-related problems. I tried to use it with Sumatra PDF, but nothing seemed to happen, apart giving me this new option the next time I tried. Then I noticed Sumatra was said active in the Windows processes, but not working. Then I found that, starting Sumatra first then giving the Open With, it all went good, but this may be caused by my Sumatra, as it is a Portable version, who knows.
Thanks again
