You could use a .VBS file and Windows Scripting Host (WSH) to search through the registry for an entry for the SMS client. For example:
WScript.Echo InstalledApplications(".")
Function InstalledApplications(node)
Const HKLM = &H80000002 'HKEY_LOCAL_MACHINE
Set oRegistry = GetObject("winmgmts://" _
& node & "/root/default:StdRegProv")
sBaseKey = _
"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\"
iRC = oRegistry.EnumKey(HKLM, sBaseKey, arSubKeys)
For Each sKey In arSubKeys
iRC = oRegistry.GetStringValue( _
HKLM, sBaseKey & sKey, "DisplayName", sValue)
If iRC <> 0 Then
oRegistry.GetStringValue _
HKLM, sBaseKey & sKey, "QuietDisplayName", sValue
End If
If sValue <> "" Then
InstalledApplications = _
InstalledApplications & sValue & vbCrLf
End If
Next
End Function
Copy and paste this text, and save it as a .VBS file. When it runs, it will show you what applications are installed on the system. Then you can incorporate this into a larger script that would save the results of the function into a variable and you could search through to see if the SMS client was listed.
Hope this helps.
Cheers,
Shawn