We can debate the idiosyncrasies of windows and application developers, but to stay in a user reality we must understand that the windows system drive is not a desirable place to store our data files for a lot of obvious reasons.
I have chosen to place all my static files and my projects to a network drive, however the location can be a local drive or even a USB drive since I got tired of windows constantly changing my environment with security "updates".
Since I am lazy by nature and all versions of Eagle uses environment variables as per all of their documentation, you need to set:
EAGLE_HOME = "\\SERVER\Eagle" <For network or> "D:\Eagle" <for drive D:>
HOME = "\\SERVER\Eagle" <For network or> "D:\Eagle" <for drive D:>
Of course in both cases without quotations.
This will allow any version of eagle to work with "your" files (and retain them after upgrades) by making the followingentries in EAGLE>Options>Directories:
Libraries = $HOME\libraries\Common;$HOME\libraries*****Will need to add all your directories*****
Design Blocks = $HOME\design blocks
Designe Rules = $HOME\design rules
User Language Programs = $HOME\ulps;$HOME\ulps\pcb-gcode
Scripts = $HOME\scripts
CAM Jobs = $HOME\cam
Projects = $HOME\eProjects
Simulation Path = $EAGLEDIR\ngspice\bin
SPICE Modules = $HOME\EAGLE\spice
My \\SERVER\Eagle folder contain the following folders: