In the event you're installing some version of Windows using one of the more well-known boot floppies passed around online, you may find Setup gets jammed on a file called BANANA.ANI. Being an animated mouse cursor, this file is definitely not integral to the installation, but you may still want to stop your Setup programs from pestering you about it anyway.
The fix is really simple; all you have to do is change a few words in CONFIG.SYS and AUTOEXEC.BAT, the configuration files used to load a real mode CD-ROM driver and whatever else is on there.
Edit a line in CONFIG.SYS that looks something like this:
Change banana to something that isn't known as a file used by Windows; I prefer something like MSCD0001. Save the file, and now edit a line in AUTOEXEC.BAT that looks like this:
Also change banana to MSCD0001 here. Save the file, restart with the modified boot disk, and you should see that your CD-ROM drive is usable and doesn't conflict with BANANA.ANI.
See, DOS can be pretty strange as a device name is treated as a file to some degree, and even without an extension, it can override an existing file as long as the driver is loaded. By using a device name that doesn't match up with any known files, you avoid bothersome file copying errors in your Setup program.