That would have nothing to do with rooting - if all you did was copy a couple of files to the phone and install an app (which is what rooting is). If you ran a rooting program, who knows? It could have also removed that option. If by "rooting" you mean that you flashed a rooted ROM, that ROM may not have an update option.
We don't have enough information at this to do much more than give you possibilities. (And if you used a rooting program, only the developer who wrote it knows what it does.)