I have a fix for the shutdown problem. I am using RPC-1 card on my Windows 7 32-bit and 64-bit PCs. Both work very well except the PCs hang during shutdown. I found this fix on the web.
There are 2 Windows services that is causing the problem. Need to force the 2 services to stop before shutdown using the following batch file.
1) Create a batch file named "AudioStop.bat" using a text editor (notepad will work)
2) Right Click on newly created .bat file >"edit" and enter following 2 lines:
net stop "Audiosrv"
net stop "AudioEndpointBuilder"
3) Save file as "AudioStop.bat" in directory c:\ProgramData\
4) Open "run" from start menu and enter "gpedit.msc" (without quotes) and hit "OK"
5) Now navigate on left pane of window "Computer Configuration" > "Windows Settings" > "Scripts (Startup/Shutdown)"
6) On right pane of window, double click on "Shutdown"
7) From window that opens, Click "Add" then browse to where you saved "AudioStop.bat" earlier and double click on it
8) Hit "Apply" and close.
You are done

Window7 will now Automatically stop the Audio services when Shutting Down or Restarting allowing system to complete the process.