1. Mount with DOSBox or DTLite.
1.1. Do not forget to mount _something_ as disc C (where you'll install Ravenloft)
1.2. If it was DTLite, mount disc as CD.
2. Go to your CD ([mounted disc letter]:, for example
d:). Find installer with
list /p (usually it's something like install.exe). Run it, typing it's name (
install.exe, if it is the case. You can omit .exe bit).
3. Follow the instructions on screen.
4. Do not forget to mount disc again each time when you going to play Ravenloft.