Help Installing APK files from Internal Storage.

[Mossey]

My Nexus does not have an Microsd slot, so I understand when using Win7 (64) that you should only have to connect to PC and be able to transfer files, right? I moved some apps(APK) files to the download folder on Nexus thinking I would install from there. Not visable on Nexus. Also tried to locate Photos in Nexus Photo file for transfer to PC, nothing there. What's am I missing. I found a work around but have no idea, now or why it works. I installed Wifi file explorer from play store, ( don't understand it either) but then the APK files were visable on the Nexus. Please explain!
What would be the advantages to rooting the Nexus?

Thanks guys

 

[Trel]

you need a file manager to get to and run the apk files
something like astro should work fine.

for the photos, start looking in DCIM

 

[Lohung]

Best FREE File Manager IMO Astro File Manager

Best PAID File Manager Root Explorer