Deploying security updates on wrkst

I need to find a way to deploying the Microsoft Security updates to the workstations without physically going to each of them. I have a mixed Windows 2000/NT 4.0 network, with 50 NT 4.0 clients, and 10 Windows 98 clients. They all run login scripts.

Is there any way I could run the security updates from a login scripts? or schedule those to run when the user logs in next?

Any help on this will be greatly appreciated.

Thanks.