a multi nation company how can they improve their security and connection speed?

Answer 1

well first of all increase the bandwidth to improve connection speed..... then for security there are 101 ways to do it like.... getting a gud enterprise firewall
getting a router with an embedded firewall (the best solution)

setting up Active directory in such a way so that users do not have a lot of access on there computers

Answer 2

Typically by buying more bandwidth and improving their firewalls. If they already have an internal network or VPN, that might need upgrading too.