Vbscript using Manufacturer to run a program install

Question

Hello, I'm new to scripting and was looking for assistance on my attempt to use a vbscript to install a program based on manufacturer detected. Basically, I would like to have the script detect if it is a Dell or an ASUS system then depending on what is
detect run an executable.
The reason for this is during OS installs or re-installs the executable pulls the serial number to be part of the naming convention. Different manufacturers store this is different areas, especially on older systems. I wish I could say we were a single manufacturer
facility but we are not. We have many beyond the Dell & ASUS systems but I would like to get it working with these just to get started. I can add more after I get something that works.
After learning things reading the forums here and elsewhere, I've seen different ways to attempt this. Unfortunately so far, I have ended in failure. I have seen the possibilities of using some of the tools to possibly re-do the rename, but that is for another
time and another project. Below is my current script and after cleaning syntax errors etc. it goes through but does not do anything. It seems like it skips over the manufacturer detect. Any assistance would be greatly appreciated.  
On error resume next
Dim strComputer, objWMIService
strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
    & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set colItems = objWMIService.ExecQuery("Select * from Win32_ComputerSystem")
For Each objItem in colItems
    If obj.manufacturer="Dell INC." Then
    Set objshell = wscript.createobject("Shell.Application")
    objshell.ShellExecute "C:\Temp\Dellrename.exe"
    Set obj.Shell = Nothing
    ElseIf obj.manufacturer="ASUSTek Computer INC." Then
    Set objshell = wscript.createobject("Shell.Application")
    objshell.ShellExecute "C:\Temp\Asusrename.exe"
    Set obj.Shell = Nothing
End If
Next
wscript.quit

Answer 1

As JRV said you need to turn off on error resume next.  You also were refering to the wrong obj in your comparison.  It needs to be objitem instead of obj.  I have reformated the code so it is more readable and added a display of the manufacturer. 
It may not be exactly as you expect.  try this and once you find the correct string you can remove or comment the wscript.echo statement.
rem On error resume next
 Dim strComputer, objWMIService
 strComputer = "."
 Set objWMIService = GetObject("winmgmts:" _
     & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set colItems = objWMIService.ExecQuery("Select * from Win32_ComputerSystem")
For Each objItem in colItems
     wscript.echo objitem.manufacturer
     If objitem.manufacturer="Dell INC." Then
         Set objshell = wscript.createobject("Shell.Application")
         objshell.ShellExecute "C:\Temp\Dellrename.exe"
         Set obj.Shell = Nothing
     ElseIf objitem.manufacturer="ASUSTek Computer INC." Then
         Set objshell = wscript.createobject("Shell.Application")
         objshell.ShellExecute "C:\Temp\Asusrename.exe"
         Set obj.Shell = Nothing
 End If
 Next
 wscript.quit