A bare repository has no working copy. That is why it seems that it is not "there" on the server. But is is indeed on the server. Otherwise you wouldn't be able to push/pull/clone it.
To show the historical information for that bare repo, you have to change directory to the bare repo and run a
git log command. E.g. like this:
git log --graph --date-order --decorate --all --stat --no-color
It shouldn't be too difficult to capture this output and make a webpage out of it.
Instaweb is a Bourne Shell script that also calls Perl and uses some Perl modules. It will not work on windows out-of-the-box. The same goes for gitweb itself which is a Perl script.
By installing the appropriate software, it should be possible to get gitweb to work on Windows but it will probably be a lot of work.
Git is native to Linux/UNIX and Windows doesn't come with the infrastructure that Linux/UNIX users take for granted. A lot of the web interfaces for git are built for UNIX-like operating systems and depend on the tools that are generally available on those platforms.
There are relatively few frontends for the Microsoft stack. One is WebGitNet. Another is GitStack. Gitblit is based on Java. Have a look at those.