To reproduce:
1. use Windows95 ( I own such a system so I won't say this is your first mistake )
2. set $HOME=D: ( actually set it to anything you like )
3. use MKS Toolkit Korn Shell : sh
4. try to launch appletviewer.

You get an error like:

Creating F:/\\.hotjava directory...
Cannot write...

and it quits.

Workaround ( this is easy, but you have to know ) DO NOT set $HOME. If your MKS environment sets it, unset it.

If you find another workaround, let me know, please.