After you open the windbg, you need to setup the following variables:
1. Check the symbol search path:
.sympath
2. Setup the symbol search path:
.symfix c:\wdbsymstore
or set up _NT_SYMBOL_PATH environment variable as following:
"c:\wdbsymstore;srv*c:\symbols\web*http://msdl.microsoft.com/download/symbols”
3.Display, set, change, or append to the source path
.srcpath (Set Source Path)
4.Enable symbol search verbose
!sym noisy