It was a joke, because ISO is a file copy of a CD-ROM disc. ;)

DOS mostly predates CD-ROM.

The DOS heyday was the 1980s.

No officially-released version of DOS contains generic CD-ROM drivers; the last few DOSes (MS-DOS 6.x, DR-DOS 6/7) contain the redirector (`MSCDEX.EXE` or equivalent) but not the device driver.

From 1992, Windows 3.1 rapidly took over.

The first mass-market CD-ROM drives were the mid-1990s, and ATAPI CDs that could attach to an EIDE interface only became common in the latter half of the 1990s, when Windows 95 was the default PC OS.

Microsoft never shipped any version of Windows 3.x on CD; I used to have a Gateway 2000 WfWg3.11 CD in my travelling toolkit, just in case. Windows 95 originally shipped on 13 1.4MB floppies.

https://archive.org/download/microsoft-windows-95_202404

The original comment was regarding Windows not specifically DOS, someone else inferred DOS from the comment.

On that note, FreeDOS does support CD-ROM.

I know. (I've reviewed it and am on its mailing lists; I've contributed a tiny handful of fixes to FreeGEM.)

So does the Win98 emergency boot diskette.

But both post-date Win95.