How to find out if user runs as administrator

[Michael Zimmer]

Wrote a liitle application which works great with XP.
I use a checkbox to install the program to c:\programs\..., just a copy-installation.
As a normal user with VISTA you are not allowed to write anything to c:\programs.
Of course i can include a manifest to make sure the program runs only with administrative rights, but for normal operation a normal user has enough rights.

Now my thought is: i would disable the installation checkbox, if the program runs with normal user rights, when started as administrator the checkbox will be enabled. But how can i determine at runtime if the current user has administrative rights?

[Hanns Ackermann]

What's about this one, posted by Semen some years ago?

http://www.powerbasic.com/support/pbforums/showthread.php?t=7462&highlight=isadmin

Regards, Hanns.

[Michael Zimmer]

Yes it works with XP, but only partially with VISTA. Even if a user is member of the local administrators Semens code only determines a normal user.
I have googled this issue and found Junfeng Zhang's notes:

In Vista, even if the user is in administrators group, the OS will create a filtered user token. The full token is linked to the filtered token, and can be retrieved with API GetTokenInformation with the new TokenLinkedToken information type.

This is a beginning, thanks. Will try with this code and tell you results later...

[Egbert Zijlema]

Possible code to test registry access

Hello Michael,

What I always do to test if a user has allround registry access, is the following. Try to open with %KEY_ALL_ACCESS an "administrator key", for instances in %HKEY_CLASSES_ROOT. Or try one from inside your own proggie if you are 100 percent sure that admin-rights are necessary. Intercept %ERROR_ACCESS_DENIED and display a messagebox.

If the result of the function is %ERROR_SUCCES (= 0; Microsoft logic?) either close the key immediately or, if it is the "real" key, process the key according to your code. Here follows a piece of code that maybe useful (not tested under Vista!). It's granted to the public domain on February 6, 2008.

#COMPILE EXE
#DIM ALL

#INCLUDE "WIN32API.INC"                                        ' Last Update: 27 January 2005

'********************************************************************************************
'* FUNCTION TestRegistryAccess                                                              *
'* ===========================                                                              *
'* This function tests whether a user has sufficient registry access or not.                *
'* In order to get access to %HKEY_CLASSES_ROOT, one must be logged on as an administrator. *
'* The class ID used here is the one for the recycle bin.                                   *
'* Alternately you may want to do this test using one of the keys your program              *
'*                                                               really needs to open.      *
'********************************************************************************************
FUNCTION TestRegistryAccess() AS LONG
  LOCAL hKey AS DWORD, iRet AS LONG
  LOCAL szKey AS ASCIIZ * %MAX_PATH

  szKey = "CLSID\{645FF040-5081-101B-9F08-00AA002F954E}"
  iRet = RegOpenKeyEx(%HKEY_CLASSES_ROOT, szKey, %NULL, %KEY_ALL_ACCESS, hKey)
  IF ISTRUE(iRet) THEN
    FUNCTION = iRet
  ELSE
    RegCloseKey hKey
    FUNCTION = %ERROR_SUCCESS
  END IF
END FUNCTION

FUNCTION PBMAIN () AS LONG
  LOCAL iRet AS LONG, sMessage AS STRING
  iRet = TestRegistryAccess
  SELECT CASE AS LONG iRet
    CASE %ERROR_ACCESS_DENIED
      sMessage = " No registry access!" & $CRLF & _
                 " In order to proceed, reboot your system" & $CRLF & _
                 " and log on as an administrator."
      MSGBOX sMessage, %MB_OK OR %MB_ICONEXCLAMATION OR %MB_TASKMODAL, " ERROR!"
      EXIT FUNCTION

    CASE %ERROR_SUCCESS
      ' no error, so no exit

    CASE ELSE
      MSGBOX "An unknown error occurred. Try again later.", %MB_OK OR %MB_ICONEXCLAMATION OR %MB_TASKMODAL, " ERROR!"
      EXIT FUNCTION
  END SELECT

  ' proceed your code here
END FUNCTION

[Michael Zimmer]

Neils code with Semen's addition is working properly for me (within NT-domain) even with Vista as client and more than one user logged on.
Egberts idea plain simple, but i prefer the first solution.
Thanks.

[Michael Mattias]

> use a checkbox to install the program to c:\programs\..., just a copy-installation.

Or, you could use an installer program (eg Inno setup http://www.jrsoftware.org) .

All the decent installer software handles all that elevation stuff, PLUS provide a clean "UN-install".

It's a thought...

MCM

[Michael Zimmer]

Of course i could use Jordan's Innosetup or NSIS or InstallShield, but the the point is:
Now i have a program, round about 200 kB, which i can run from USB stick and if i like install to the PC. All with one file, no separate installer neccessary.
=> that's really simple

[Francisco Castanedo]

I'm afraid it does not work for me (Egbert's code). I'm running as administrator in Windows 7 Ultimate 32-bit.
Even with elevation by means of a manifest, it does not work either.

[Francisco Castanedo]

Semen's solution works like a charm in XP Sp2, Vista y 7!!!