IIS7 issue. I cant edit or add files in the "wwwroot" folder under "inetpub"

Hi All,
I have a web app thats in a VM and has IIS installed.
I need to be able to change some configuration settings in the file and save it.
But it won't save saying access is denied. I can t drag any new files to it either.
Whats the best approach to fix this?
I tried adding my self to the admin group but didn't work.

Any tips and resources that can help would be great.