The first step is to find the project project file:
Step 2: Edit the project file
Find Format Version 12.00 and change the number to 11.00
Find #Visual Studio 14 and change the number to 2010
Click save and close
The third step, open the project file
The fourth step, edit the project file
Right click - open the file with notepad
Find ToolsVersion = "14.0" and change the number to 4.0
Then Ctrl+F find v140 (there are four places in total) and delete all four lines containing v140
save and exit
end