Sometimes you may need to run Visual Studio as Administrator; to do so, you have to right-click on Visual Studio task bar shortcut, right-click again on Visual Studio and select Run as Administrator. Then, you may open the solution you want manually from File -> Open -> Project/Solution or drop your .sln file onto Visual Studio.
To make your life easier, you may perform the following tasks in order to start as Administrator faster.
Open Visual Studio as Administrator
If you want to start Visual Studio as Administrator you can do the following:
Open every Visual Studio Solution (.sln) as Administrator
Although not the best idea if you open third-party VS solutions, it may come in handy if you need to open the same solutions as Administrator again and again. To do so, right-click on devenv.exe and select Troubleshoot Compatibility.
You may then proceed to the following steps:
Following the above, whenever you open a solution (.sln) it will always open as Adminsitrator. If you want to disable this function, you will need to follow again the steps above without checking though The Program requires additional permissions.