Just found a dell broshure which says the Inspiron 7591 2-in-1 supports Microsoft Pen Protocol. The brochure: [URL] Hopefully, this helps anyone with the same problem.  
I have the Dell Inspiron 15 7591 2-in-1 running Windows 10 and was wondering whether there any alternatives to the pn350m for my laptop since the first one I had was replaced by warranty due to it simply not working many times and the second one just completely failed again? If not, does my device support either Wacom Active ES protocol or Microsoft Pen Protocol? Just to make this clear, this is not a problem with the battery since I have tried replacing it with fresh ones and the pen was in great condition. I can also confirm that I am not the only one struggling with this since I have seen many reviews and posts claiming that the pen was great up until it would begin struggling with connecting to the laptop.  Here is a small reddit forum if you do not believe me: Problems with the PN350M pen : Dell (reddit.com) And another one: Inspiron 15 7500 silver 2-in-1 with Active Pen PN350M : Dell (reddit.com) And guess what? Another one: Dell Inspiron 13 (7375) compatible pen? : Dell (reddit.com) And from the support forums: Dell active pen PN350M not working with 17 7000 2in 1 - Dell Community I mean, I found something on Ask Ubuntu claiming that the pen uses Microsoft Pen Protocol to connect to computers, but why would I trust someone (just to be clear, I am on Windows): xinput - Dell Active Pen PN350M not working properly - Ask Ubuntu So in reality, was this pen actually designed to last as long as possible or was it built to fail in a given amount of time? At the end of the day, I just don't care and want to use a pen that will work consistently and have better support than being told it must be the battery. So once again, I have the Dell Inspiron 15 7591 2-in-1 and was wondering whether there any alternatives to the pn350m for my laptop since the first one I had was replaced by warranty due to it simply not working many times and the second one just completely failed again? If not, does my device support either Wacom Active ES protocol or Microsoft Pen Protocol? I do not even want to bother trying to get this pen fixed or replaced because I am willing to bet that if I buy this pen again that the same result will happen most likely due to planned obsolescence which is sadly not a crime, but a very pitiful move, I just want to find a good pen to replace it.
Dell Inspiron 15 7591 2-in-1 Pen Compatibility