I have gVim 7.4.608 installed on Windows 7 at work.I've looked in C:\ , C:\Users\<username>\AppData , C:\Program Files\vim , C:\Temp but there's no sign of it. It must exist somewhere, command history is working OK. I just want to read the file, I don't care where it actually is.From :help viminfoThe default name of the viminfo file is $HOME/.viminfo for Unix and OS/2,s:.viminfo for Amiga, $HOME\_viminfo for MS-DOS and Win32.  For the lasttwo, when $HOME is not set, $VIM\_viminfo is used.  When $VIM is also notset, c:\_viminfo is used.  For OS/2 $VIM/.viminfo is used when $HOME isnot set and $VIM is set.The variables %HOME% and %VIM% were not set in my Windows environment.I couldn't look in directory C:\Users\<username>\Application Data.
Where is my viminfo file on Windows?
gvim;persistent state;microsoft windows
For Windows, the home directory is set in %USERPROFILE%. I believe vim will use this as $HOME.In my case, the _viminfo is located in the C:\Users\<username>, which is the home directory, while the %HOME% is not set as well. 