Replacing Text in Doc via VBScript w/o Error

Hi, all!  I have a script to replace text from an INS file, but I need it to not display an error AND end the wscript.exe process if it errors out, like when the path is not found on certain operating systems.  The script will be tied to a GPO to run at logon.

Here is the script:

Const ForReading = 1
Const ForWriting = 2

Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile("C:\Windows\System32\GroupPolicy\User\MICROSOFT\IEAK\install.ins", ForReading)

Do Until objFile.AtEndOfStream
    strLine = objFile.ReadLine
    If InStr(strLine, "FavoritesDelete") = 0 Then
        strNewContents = strNewContents & strLine & vbCrLf
    End If
Loop

objFile.Close

Set objFile = objFSO.OpenTextFile("C:\Windows\System32\GroupPolicy\User\MICROSOFT\IEAK\install.ins", ForWriting)
objFile.Write strNewContents

objFile.Close

The way that it is, it works, but, again, errors out on some operating systems.  I tried On Error Resume Next, which hides the error message, but then pegs the wscript.exe process at 99%.  And the error message returns if I use the following code:

If Err <> 0 Then
    Wscript.Quit
End If

Any help is appreciated.  Thanks!

Brandon