The AppSense Performance Suite helped EWS to prevent staff from installing their own applications and playing computer games, a spokesman for the firm said.
"There is a wide range of users, from finance people to train drivers," said Matt Crayton, head of IS infrastructure for EWS. "Some of them are in very remote locations. Now we feel happy that about the operational security on the network."
The solution works by only processing network traffic that is acceptable to the server.
EWS will initially rollout the AppSense Performance Suite to 450 staff and then it to more than 2000 others in the coming months.