[python-win32] Querying the VNC Service fails sometimes

[Mike Driscoll]

Mike Driscoll wrote:
> Hi,
>
> In one of my login scripts for work, I run a query to see if the VNC 
> service is running using the win32serviceutil module. The code for 
> that I am using looks something like this:
>
> <code>
> import win32serviceutil
> serviceState = win32serviceutil.QueryServiceStatus('VNC Server')[1]
> </code>
>
> This works in 99.99% of cases. However, I have on user that keeps 
> getting the following traceback:
>
> Traceback (most recent call last):
>  File "\\ourServer\pathName\PostLogon.py", line 207, in ?
>    serviceState = win32serviceutil.QueryServiceStatus('VNC Server')[1]
>  File 
> "\\ourServer\pathName\Python24\lib\site-packages\win32\lib\win32serviceutil.py", 
> line 479, in QueryServiceStatus
>    hs = SmartOpenService(hscm, serviceName, 
> win32service.SERVICE_QUERY_STATUS)
>  File 
> "\\ourServer\pathName\Python24\lib\site-packages\win32\lib\win32serviceutil.py", 
> line 81, in SmartOpenService
>    name = _GetServiceShortName(name)
>  File 
> "\\ourServer\pathName\Python24\lib\site-packages\win32\lib\win32serviceutil.py", 
> line 62, in _GetServiceShortName
>    skey = win32api.RegOpenKey(hkey, svc, 0, access)
> error: (2, 'RegOpenKeyEx', 'The system cannot find the file specified.')
>
>
> I used regmon to try and figure out what part of the Registry my code 
> looks at and it appears to be looking for the "DisplayName" value in 
> HKLM\SYSTEM\CurrentControlSet\Services\winvnc
>
> I cannot see a difference in this user's registry versus my own, which 
> does not have this issue. However, I can duplicate the error by 
> connecting to the user's PC's registry using the _winreg module and 
> querying the "DisplayName" value, like this:
>
> QueryValue(key, 'DisplayName')
>
> Which give me this traceback:
>
> Traceback (most recent call last):
>  File "<pyshell#14>", line 1, in <module>
>    QueryValue(key, 'DisplayName')
> WindowsError: [Error 2] The system cannot find the file specified
>
> But if I use use _winreg's EnumValue, I get this:
>
>>>> EnumValue(key, 4)
> ('DisplayName', u'VNC Server', 1)
>
> What the!? Does anyone have any suggestions? Maybe a better way to get 
> the information? I only need to know if the service is running or not, 
> and if not, to start it.
>
> Thanks!
>
>

I forgot to mention that we use Windows XP, Python 2.4 and PyWin32 
version 210.

Mike