how big is dos 6.22 after being installed

MS-DOS 6.22 is very small after installation: roughly under 7 MB on disk, and in some setups the core DOS memory footprint can be much smaller than that. A forum report specifically says a fresh install in a virtual machine used a little under 7 MB, and another source notes the DOS system itself can be trimmed down to about 16 KB of conventional memory usage in a minimal configuration.

Installed size

The most practical answer is:

• Full installed disk space: about 7 MB.
• Bare minimum core DOS footprint in memory: around 16 KB in an optimized setup.

That old software was designed for tiny hard drives and floppy disks, so the installation is surprisingly light by modern standards. MS-DOS 6.22 also shipped on multiple floppy disks, which lines up with its small overall size.

Quick context

If you’re asking because you want to run it in a VM or retro PC, planning for 10 MB or so is usually plenty comfortable. If you’re trying to keep it extremely lean, the exact total can vary a bit depending on drivers and config files you add.

TL;DR

MS-DOS 6.22 installs to about 7 MB , give or take a little depending on configuration.