Update README.md

Author: dylanmei

README.md

@@ -17,8 +17,8 @@ Currently, this repo expects you to do a little heavy lifting to get the Windows
 3. Clone this repo to a local directory
 4. Create a directory named `iso` in the root of the repo
 5. Move `en_windows_server_2008_r2_with_sp1_x64_dvd_617601.iso` to the `iso` directory
-6. Run `packer build windows.json`
+6. Run `packer build windows_2008_r2.json`
 
 ### Contributing
 
-Pull requests welcomed. I plan to include other variants of Windows 2008 R2 and Windows 2012 next.
+Pull requests welcomed. I plan to include other variants of Windows 2008 R2 and Windows 2012 next.