Error: The process cannot access the file c:\users\word file.docx because it is being used by another process in ASP.Net

what is virtual path..i tried the code in this site and i have error in this statement :

--- FileUpload1.SaveAs((Server.MapPath("~/Temp/") + Path.GetFileName(FileUpload1.PostedFile.FileName)))---

what path should i use and how i can use networkpath or phisical path