When I try to open ASP.NET Configuration, I get the follow error

I've tried all the available solutions from google, but none of them worked and some of them were posted before 2010, anyone have a solution for vs2010?
I finally fixed it, here is what i did:
- Find a computer that has ASP.NET configuration working(i was lucky enough that asp.net configuration on my pc is working, if you don't have one, you can message me, i am happy to provide one if your framework version is 4.0.3031).
- Copy all the files under C:\Windows\Microsoft.NET\Framework(your version)\asp.netwebadminfiles into a usb.
- Go to the pc with the problem and go to the same folder, cut and paste the files inside that folder in a new folder(for backup purpose, in case something goes wrong).
- Copy/Cut and paste the working files in your usb to that folder and all is done.
- If the target framework error is showing, just change the target framework in web.config to the correct framework.
Hope this helps, i was frustrated for days that there isn't a solution and this just popped up in my mind, very happy :)