Rufus is an excellent tool for creating bootable media under Windows. However, the option to create bootable MS-DOS media was lost some versions ago.

Windows 10 specifically is missing diskcopy.dll which is needed to properly create MS-DOS bootable media. This file is now only present in earlier versions of Windows. ^[1]

Collect files

First we need to gather an old version of Rufus, version 2.2 to be exact. It can be found on GitHub:

• https://github.com/pbatard/rufus/releases/download/v2.2/rufus-2.2.exe
• https://github.com/pbatard/rufus/releases/download/v2.2/rufus-2.2p.exe (Portable)

Next we need the patch file which is still available on Lenovo's servers as of 2026-08:

• https://download.lenovo.com/pccbbs/thinkservers/rufuspatch.zip

Create MS-DOS media using Rufus

1. Start Rufus
2. Open the log
3. Select your USB drive
4. Set to FAT or FAT32
5. Set to MS-DOS
6. Start
7. Wait for the error:

Unable to open C:\windows\system32\diskcopy.dll: [0x0000007E] The specified module could not be found.

8. Close rufus
9. Copy the files from rufuspatch.zip to the USB drive
10. Done! Now you have a bootable MS-DOS drive on Windows 10

Note: Make sure the BIOS is set allow booting in compatibility mode. MS-DOS does not natively understand UEFI.