missing using directive or assembly reference
would be enough. Learn about references for projects in VS, find which one is missing and add it.
Probably you have to fix reference to some sdk library because you have it in another directory than it was present for developer who created the sample.
In solution explorer you have solutions and there are References
check if there is something with exclamation mark, or search on msdn for class that is causing the issue in which library it is present. Then you can find library in sdk and set correct path to it.