Hight light the variable in the whole document
choose the variable and then click “shit + F8”
Add search path for header files
Under Options->Preferences->Project Symbol Path, add the absolution path which is splited by semicolon.
Add directory for common library
Once installed source insight, there is a common project dialog could be seen. If missing, click option/preferences/Symbol Lookups
Under the common projects, you could add for common c++, windows sdk, java, dot net framework
click continue to add the project one by one.
After create all the common project, create your own project and configure the lookup symbols