Python Cookbook

Getting the Windows Service Name from Its Long Name

Credit: Andy McKay

Problem

You need to find the actual name of a Windows service from the longer display name, which is all that many programs show you.

Solution

Unfortunately, a Windows service has two names: a real one (to be used in many operations) and a display name (meant for human display). Fortunately, Python helps you translate between them:

import win32api
import win32con

def GetShortName(longName):
    # Looks up a service's real name from its display name
    hkey = win32api.RegOpenKey(win32con.HKEY_LOCAL_MACHINE,
        "SYSTEM\\CurrentControlSet\\Services", 0, win32con.KEY_ALL_ACCESS)
    num = win32api.RegQueryInfoKey(hkey)[0]

    # Loop through the given number of subkeys
    for x in range(0, num):
        # Find service name; open subkey
        svc = win32api.RegEnumKey(hkey, x)
        skey = win32api.RegOpenKey(win32con.HKEY_LOCAL_MACHINE,
            "SYSTEM\\CurrentControlSet\\Services\\%s" % svc,
            0, win32con.KEY_ALL_ACCESS)
        try:
            # Find short name
            shortName = str(win32api.RegQueryValueEx(skey, "DisplayName")[0])
            if shortName == longName:
                return svc
        except win32api.error:
            # in case there is no key called DisplayName
            pass
    return None

if _ _name_ _=='_ _main_ _':
    assert(GetShortName('Windows Time') == 'W32Time')
    assert(GetShortName('FoobarService') == None)

Discussion

Many programs show only the long description (display name) of a Windows Service, such as Windows Time, but you need the actual service name to operate on the service itself (to restart it, for example). This ...