Ricardo, se quer ver se existe impressoras instaladas segue o codigo 
strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set colInstalledPrinters = objWMIService.ExecQuery _
("Select * from Win32_Printer")
If colInstalledPrinters.count = 0 then
wscript.echo "não existe impressoras instaladas"
else
wscript.echo "existe impressoras instaladas"
end if