[JustSomeGuy]

I'd like to create some custom file properties for the purpose of defining
metadata about the content of the files, so I can use 'search file
properties' to locate files with desired content...just like big time
electronic document management systems can do.

But when I open the file properties window of my docs, it doesn't let me
define any custom properties. I suspect this is because in the General tab
of file\properties, they're marked 'archive' for some unknown reason, and the
setting is greyed out and can't be changed. Where am I going wrong?