How to execute program on remote computer?

 
Several days ago I faced with a simple task - I had to execute program (automated QTP test in my case) on several remote computers.
My goal was simple - if I can execute scripts on my computer, then why don't we execute them on remote computers?


I think, this task is very interesting and practical, isn't it? :)

There was one condition. I tried to use "native" Windows solutions, which do not require additional installed software or libraries. I didn't want to use external soft, files, etc.

As a result, I found two solutions. Both of them use WMI:

1. Win32_Process Class
2. Win32_ScheduledJob Class

I will describe both of them.
Running ahead, I will say that I decided in favour of second solution (Win32_ScheduledJob class).


Let's explore these solutions, and compare them.
For clarity, I will show how to execute simple application (notepad.exe) on remote computer.

1. Execute program on remote computer with Win32_Process сlass
   To create and start new process, I used Create method of the Win32_Process class.
   VBScript code is simple enough:
   
   
   

   1. strComputer = "."
   2. strCommand = "notepad.exe"
   3. 
      
   4. Set objWMIService = GetObject("winmgmts:" & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
   5. Set objProcess = objWMIService.Get("Win32_Process")
   6. 
      
   7. errReturn = objProcess.Create(strCommand, null, null, intProcessID)
   8. 
      
   9. If errReturn = 0 Then
   10. Wscript.Echo "notepad.exe was started with a process ID: " & intProcessID
   11. Else
   12. Wscript.Echo "notepad.exe could not be started due to error: " & errReturn
   13. End If
       
       
   
   String strComputer = "." means "local computer".
   So, the result of notepad starting on my local computer was:
   And notepad started on my computer! Great!
   
   Then I tried execute my script on remote computer (I set strComputer = "servername"). The result was:
   Script said, that the process was created.
   Indeed, process was created. It was shown in Task Manager on remote computer:
   But I didn't see it on a desktop of remote computer!
   Further investigations shown, that:
   For security reasons the Win32_Process.Create method cannot be used to start an interactive process remotely.
   
   Win32_Process class is very useful to create and execute batch tasks on remote computer. But it can be applicable for interactive processes.
   
   That's why I preferred the second way. I mean Win32_ScheduledJob сlass.
   
   
   
2. Execute program on remote computer with Win32_ScheduledJob сlass
   By analogy, to create and start new process, I used Create method of the Win32_ScheduledJob class.
   VBScript code is :
   
   
   

   1. strComputer = "."
   2. strCommand = "notepad.exe"
   3. 
      
   4. Const INTERVAL = "n"
   5. Const MINUTES = 1
   6. 
      
   7. Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
   8. Set objScheduledJob = objWMIService.Get("Win32_ScheduledJob")
   9. Set objSWbemDateTime = CreateObject("WbemScripting.SWbemDateTime")
   10. 
       
   11. objSWbemDateTime.SetVarDate(DateAdd(INTERVAL, MINUTES, Now()))
   12. errReturn = objScheduledJob.Create(strCommand, objSWbemDateTime.Value, False, 0, 0, True, intJobID)
   13. 
       
   14. If errReturn = 0 Then
   15. Wscript.Echo "notepad.exe was started with a process ID: " & intJobID
   16. Else
   17. Wscript.Echo "notepad.exe could not be started due to error: " & errReturn
   18. End If
       
       
   
   Create method of Win32_ScheduledJob сlass creates new scheduled job on computer. (Hm... Have I said a tautology? :) ) In script I specified the time when scheduled job should be executed - in one minute from now. For that i used standard VBScript function - DateAdd.
   
   Hint: Some time ago I wrote an article abount time/date functions in VBScript. Read it.
   
   The result of execution was excellent! It created scheduled jobs both on local and remote computer.
   This is result for remote computer is:
   
   In one minute, the notepad was started and shown on desktop of remote computer!
   I was happy :))
   

I hope, these two methods of remote application execution will be very helpful for you. Computer should calculate, human should think :)

So, I shown how to force your computers to work.
Do you have any ideas on how to force a human to think? :)

Summary:
If you have to run batch tasks, I think first method (Win32_Process Class) is simpler.
If you have to run interactive programs, use Win32_ScheduledJob Class.


--
Dmitry Motevich