When running a native compilation of gVim under Win7 I have the following in my vimrc:
if has ("win32")
let $TMP="C:/tmp"
setlocal equalprg=tidy\ --output-xhtml\ y\ -utf8\ --wrap-attributes\ 1\ --vertical-space\ 1\ --indent\ auto\ --wrap\ 0\ --show-body-only\ auto\ --preserve-entities\ 1\ -q\ -f\ shellpipe=2>
endif
This should create a temp file. However, after running the command, I see:
shell returned 1
E485: Can't read file C:\tmp\VIoC935.tmp
The common recommendation for native windows E485 errors is to set the tmp variable, which I have, as you can see from my vimrc snippet. If I remove the let statement, I get a similar result:
shell returned 1
E485: Can't read file C:\Users\ksk\AppData\Local\Temp\VIfFA01.tmp
In both cases; both directories exist and gVim can write a file to those locations, i.e.,
:w C:\Users\ksk\AppData\Local\Temp\VIfFA01.tmp
in the current buffer will write this file without error.
Interestingly, while writing this, I found that if I create a new buffer, and delete the original buffer, the equalprg function runs without error (with and without the "let" statement in vimrc)
Interestingly, while writing this, I found that if I create a new buffer, and delete the original buffer, the equalprg function runs without error (with and without the "let" statement in vimrc)
That's probably because you use setlocal in your vimrc
E485: Can't read file C:\tmp\VIoC935.tmp
I know the reason, but I don't know how to fix it without changing indentation options. The issue is caused by the '>' symbol of your indent command, it should work after removing the last part of it or even only the '>' symbol. It's so because '>' has a special meaning in shell commands. In *nix one can probably just escape it, but this doesn't work for me in Windows.
P.S. I know this is not a full answer, but maybe it will help you solve the issue.
Update. Small discussion in the comments discovered that the correct way of escaping is to enclose the last argument in double quotes (the variant 2) below). So the working command is:
setlocal equalprg=tidy\ --output-xhtml\ y\ -utf8\ --wrap-attributes\ 1\ --vertical-space\ 1\ --indent\ auto\ --wrap\ 0\ --show-body-only\ auto\ --preserve-entities\ 1\ -q\ -f\ "shellpipe=2>"