Windows context menu "open with vim" symlink error

Question

New install of Vim 8.1.1 on Windows 10 64bit. Also running cygwin.

From a Windows Explorer r-click context menu for a file, the "Edit with Vim" produces a cmd.exe window with:

C:\WINDOWS\system32\cmd.exe /c <symlink>ÿþ/
The system cannot find the file specified.
shell returned 1
Hit any key to close this window...

I hit any key and get a Vim alert dialog saying

:!<symlink>ÿþ

Clicking ok then continues on to successfully open the file in gVim.

If I select an option to "Edit with existing vim <some already open file>", it works fine, opening up the target file in the specified existing Vim window.

I did find https://superuser.com/questions/753537/windows-vim-symlink-config-file-persistent-error. This talks about symlinks to vimrc/gvimrc files, but I case insensitive check of_all_ the files on disk with a name containing "vim" and the only ones with symlinks are for cygwin versions of things like "evim", "rvim", etc.

% for f in $(locate -i vim); do file "$f"; done | grep -i symbolic

(Note: had to muck w/ $IFS to allow spaces in Windows filenames.)

I also tried uninstalling/reinstalling VIM.

After yet more digging I found (using process explorer on the blocking cmd window) that gvim is actually executing vimrun

"C:\Program Files (x86)\Vim\vim81\vimrun" C:\WINDOWS\system32\cmd.exe /c ÿþ/

From this I found that executing gvim.exe from that vim81 folder does the same thing. It's having trouble finding the _vimrc file. If I specify -u <path to _vimrc> it works. The default location of _vimrc seems to be ...\Vim\. Just copying _vimrc to ...\Vim\vim81\ has no effect.

So now the questions maybe become

1. How to I make _vimrc findable by gvim.exe?
2. Do I need to hack the registry to add -u?
3. If so where exactly? "...\gvim.exe" "%1" occurs multiply in the reg

Been living with this for months now, but would really like to get it figured out. Thanks in advance!

Answer 1

Found a solution/hack: If you set a Windows %HOME% environment variable to a path for a folder that contains _vimrc things will work.

Experiments with MYVIMRC, MYGVIMRC, and VIM environment variables didn't work for me in spite of doc to the contrary in :help _vimrc.