First, make sure it works from the command line: DIR \\HPOne\Video\Temp\
Next, check GetLastError(). (In the debugger, you can view the result of GetLastError() using the special constant @ERR) My guess is that you are getting ERROR_ACCESS_DENIED or ERROR_PATH_NOT_FOUND.
If you are getting ERROR_PATH_NOT_FOUND, try removing the trailing backslash.