With Windows NT 4.0, 95 in that brew and the age of the machines, anything you do may result in it crashing. Even if your addon didn't do it, you would get the blame.

Don't touch these things but do the usually yearly maintenance and backup such as dusting the boxes out and replacing failed fans.

Give it another year for the hardware to fail.

In closing, there are security patches that are never going to show up for Windows NT and 95. Just so you know.

Bob