I use Secunia PSI which auto updates programs when you run it and you can also set it to have it open once the system boots and it'll check the security state of everything and notify you. Though for 100+ computer there might be a better program where you can roll out the software on every machine and monitor it on a single system instead of having to go to each machine to verify everything has been updated, i think there is a corperate version of Secunia PSI that has something similar to that, but i bet there is a cost involved.