If you are planning to use the Windows 7 SDK with RadASM's RadHelp and my Help2Viewer application this is the command line to enter for winapi.kwl in RadHelp options:
"$D\Help2 Viewer.exe" /$K /MS.W7SDK.1033/MS.W7SDKCOM.1033/
This assumes that Help2Viewer.exe is located in the radasm\addins folder.