Hate to revive an old thread but I ran nPDF on my CX CAS and it said I can now view .pdf, .html, etc files. Only issue I am having is getting .pdf files onto my calculator. I'm using the TI-Nspire CX CAS Student Software on my laptop and it tells me that .pdf files are not supported. I tried to change the file name to "filename.pdf.tns" but the software turns it into "filename.pdf.tns.pdf". I'm a newb when it comes to these things, but I am running 4.2 if that helps at all, and I do have Ndless 4.2cascx running on my calculator. 
Thanks!

---Don't know if it makes a difference but I am also running Windows 10
*****UPDATE: I got it working. Well, somewhat. My PDF is 16 pages long and about halfway through the screen goes white and shows nothing... Hmmmmm....