@patrickdrd
Windows has a builtin way to specify the starting directory for any shortcut you run – and I am assuming that since you claim to be loading a blank NPP window, you’re loading from a shortcut instead of from a Right Click menu.
To change the Windows default directory, Right Click on your shortcut, select Properties (‡), go to the Start In field, and enter the directory you’d like to be your default
‡: For a normal shortcut, like on your desktop, you just have to select Properties. If the shortcut is pinned to your taskbar (like it is for me), RClick, then RClick on “notepad++” near the bottom of the menu, then select Properties. If it’s in your Start Menu (either pinned to the quick start area, or if you go down to N > Notepad++), then RClick on the icon, select More, select Open File Location; this should open Windows Explorer in the directory where that shortcut actually lives. In that Windows Explorer, you can RClick on Notepad++ shortcut and select the Properties, as above.