Microsoft.Office.Interop.Excel reference isn't resolved

For .net developers which works with MS Office interop, maybe following information would seem useful. Did you happen to face with unresolved Office Interop references?
Each time as I saw this strange phenomena I would need some magic to resolve the problem.
Mostly the reason hides in conflicting of different asseblies references. In this case usually it's better to remove all unresolved references and add each new assembly refererence step-by-step checking conflict absence.