Gid extension is associated with Windows Help Index files. You have chance to open gid files with Windows Help.
When you open a help file with Windows Operating system, this file is created. There is no harm to delete these index files. Because Windows operating system uses gid files for the purpose of making a searches faster. However, when you make a search again at help files, gid files occur again. You don`t need an extra software to open gid files.
What to use gid
click F1 for Windows Help or help pages in Mac
which page related to gid file
gid Related Searches
You can check related links about gid fileextension.