As a possible solution, the only method that worked over USB was MTPDrive:
https://groups.google.com/forum/#!topic/alt.comp.freeware/TaIlIMK2Nuw%5B1-25%5D
Unfortunately, MTPDrive is crippleware, where it's pretty much definite
that there is no Windows freeware extant that will mount the Android
internal or external SD card contents over USB as a drive letter.
The closest we can find, together, even with our immense tribal experience,
is the long-known MTPDrive crippleware, which we all knew about _before_ we
started this quest for a freeware replacement to MTPDrive functionality
(and which has 4 critical functionality flaws which negate MTPDrive as a
general solution for everyone - which is _always_ the goal).
To add further value to the overall tribal knowledge, I have found yet
another limitation of the MTPDrive crippleware, which I encountered, just
now, when I happened to have both the Android & iOS devices connected by
USB on Windows.
I was copying over this morning the APK of my first Android app I created:
https://groups.google.com/forum/#!topic/alt.comp.freeware/qEqThtRwZAg
When this new-to-me error popped up:
"MTPDrive - Error
Trial version limit reached:
- Maximum number of mapped devices = 1"
Here is a screenshot showing the attempt to map both Android & iOS on Win:
http://www.bild.me/bild.php?file=2725206dir028.jpg
In my experience, these are the 4 limitations of the MTPDrive cripplewa
o Only 1 mobile device can be mounted per session
o Only 30 files can be copied per session
o On the _external_ sdcard seemed to be mountable (not internal storage)
o The Dokan Library used by MTPDrive & FTPUse are apparently incompatible
http://www.bild.me/bild.php?file=8315262dir03.jpg
Otherwise, MTPDrive crippleware works perfectly on Windows to mount the
Android internal and external sd card contents over USB as a drive letter.
In summary, nobody on any of these newsgroups knows of any working general
solution to the problem of mounting the Android internal and external
storage as a drive letter on Windows over USB such that all Windows
commands work:
http://www.bild.me/bild.php?file=1853998dir02.jpg
The best Windows solution is to mount Android as a drive letter over WiFi:
o WebDAV http://www.bild.me/bild.php?file=8605173dir05.jpg
o DirectNetDrive http://www.bild.me/bild.php?file=6340420dir012.jpg
o NetDrive v1.3.2.0 http://www.bild.me/bild.php?file=1383190dir014.jpg
o webdav http://www.bild.me/bild.php?file=2373390dir019.jpg
o netdrive http://www.bild.me/bild.php?file=3994244dir020.jpg
Although plenty of those solutions failed miserably in my tests:
o FTPuse http://www.bild.me/bild.php?file=7687244dir06.jpg
o FTPuse http://www.bild.me/bild.php?file=3316456dir08.jpg
o FTPuse http://www.bild.me/bild.php?file=4223201dir010.jpg
o SFTP Net Drive http://www.bild.me/bild.php?file=2809525dir013.jpg
o netuseloginport http://www.bild.me/bild.php?file=8381514dir017.jpg
o netuseloginport http://www.bild.me/bild.php?file=3626731dir018.jpg
o ftp netuse fails http://www.bild.me/bild.php?file=4233679dir018.jpg
o ftpuse works http://www.bild.me/bild.php?file=4121239dir021.jpg
o ftpuse fails http://www.bild.me/bild.php?file=5451129dir022.jpg
o ftpuse fails http://www.bild.me/bild.php?file=8726712dir023.jpg
o fptuse firewall http://www.bild.me/bild.php?file=9234464dir024.jjpg.jpg
o ftpdrive http://www.bild.me/bild.php?file=4023721dir025.jjpg.jpg
The best solution, overall, since it requires no non-native software
anywhere, is to use a dual-boot Ubuntu 18.04, which can simultaneously
read/write not only the entire visible Android filesystem over USB, but
also it has read/write access to the entire visible Windows (yes, even as a
dual boot, as long as Windows hibernation is off), Linux, & iOS file
systems:
http://www.bild.me/bild.php?file=6181360dir01.jpg