Can't edit or delete CSS file. (ASP.NET MVC)

I'm new to the whole ASP.NET MVC business, and I'm having the weirdest problem. I've been working on a project (MVC3, Razor engine) for the past few days, and yesterday I backed up my project by duplicating its folder. I opened the duplicated project and started working, but I noticed something weird. none of the changes I was making in a CSS file appeared anywhere. I tried changing all sorts of things in it, deleting its content and even deleting the whole file! nothing works. no change. After deleting the whole CSS file from my project, I tried making some changes in the .cshtml file and it does change when I d开发者_StackOverflowebug the project.

What can be the cause of this?

Your browser probably cached the CSS file. Ctrl+F5 should do the trick in most browsers, to reload the css too and make changes visible.

Sounds as a caching issue to me.

http://www.refreshyourcache.com/en/cache/

Are the files read only in the copy?