This section has details on how to install VNC to older Windows systems (95, 98 and ME). One thing I should point out is that these earlier systems don't have the same remote services that started with Windows NT. In a nutshell, it's just not possible to use FastPush on 9x clients. However, because of their lack of security you can run custom made setup programs to load the client on via a logon script.

Creating a setup.exe package

Rollout VNC to 9x via login script