The Scwcmd.exe tool is located in the %systemroot%\System32 folder.
This problem occurs because the Scwcmd.exe tool is not available from drives other than the system drive.
You try to register an extension by using the Scwcmd.exe command-line tool from a drive other than the system drive on a Windows Vista-based computer. After you do this, you may receive an error message that is similar to the following:
0x80070005 - Access is denied