How to install ReactOS into QEMU on Windows

Got a ReactOS tutorial to share? Drop it in here

Moderator: Moderator Team

Post Reply
Posts: 10
Joined: Sat Dec 01, 2007 2:04 pm

How to install ReactOS into QEMU on Windows

Post by mgmechanics »

'How to install ReactOS into QEMU on Windows? '
Version 1b

1) Prepare
First: You don't need to burn a cd. Everything runs within files on your computer.
For doing fast 'n easy (or quick 'n dirty at your option) i will do everything right in QEMU's program folder.
Because I use a virtual machine (a computer that 'lives' only in some files), i think it is ok to use an image fresh from this projects svn. You will have a better look to the progress of this project. But you can also use the released version instead.

1-1) Download QEMU for Windows from "". You should get a file named like ""

1-2) Unpack the zipfile you downloaded. A folder will be created.

1-3) Go to and download a bootable image of ReactOS, ready for installation on a harddisk (= not a Live-CD). For an image fresh from projects svn go to You should get a file named like "" for an 'official release' or 'bootcd-31113-dbg.7z' for an image fresh from projects svn. In the latter case you need 7-Zip ( for uncompress the "*.7z"-file.

1-4) Open the Windows - commandshell (Start -> Run -> cmd)

1-5) Change into the folder.

2) Create a virtual harddisk
=> Please take care: "qemu-img.exe" overwrites files without warning! *) <=

2-1) Type **) "qemu-img.exe create ros_hdd01.img 2048M" into the commandshell
"ros_hdd01.img" is your new virtual harddisk
"2048M" means that its size will be 2048 MB [= 2 GB]
its format is "raw" per default ***).
Your virtual harddisk will be created in a few seconds - no need to go for a coffee!

3) Installing ReactOS and first run
Be aware to adapt filenames on your files, especially "bootcd-30952-dbg.iso"!

3-1) Now type "qemu.exe -L . -hda ros_hdd01.img -cdrom bootcd-30952-dbg.iso -boot d"
that means:
After "-L" follows the path to a file that contains a BIOS, needed by the virtual machine like a "real" machine, the "." is a placeholder for "current directory" since QEMU comes with such a file
"-hda ros_hdd01.img" = your virtual hda is this file
"-cdrom bootcd-30952-dbg.iso" = your cdrom-drive is that file
"-boot d" means: boot from cdrom-drive

3-2) After committing this command with <Enter> the virtual machine will boot, as soon the installation of ReactOS will start

3-3) Then just walk though a simple windows installation.
A good description is available here: ... unter_Qemu
If unsure, choose the defaults. I recommend to change keyboard layout.
Hint1: Choose your screen resultion a install, default is 800x600 - this makes sure that the QEMU-window is not bigger than your desktop. Check if the resolution of your machine is bigger than 1024x768, b.d.w. 1280x800. In this case, 1024x768x16 works fine.
Hint2: The 3rd number means how many colours you will have. Decreasing number of colours will increase your systems speed - be careful to choose more than 16 (= 2^16 = 65535 colours).

After ReactOS-installation has finished, the virtual machine reboots and ask you to press any key for boot from cdrom: Just leave it alone: If not pressing any key QEMU will boot from your virtual harddisk

3-4) To start ReactOS after it is installed just type "qemu.exe -L . -hda ros_hdd01.img -boot c" to boot your ReactOS.
If you want to install software, make an iso-image (a virtual cd, most cd-burn-software can do this) and use "qemu.exe -L . -hda ros_hdd01.img -cdrom <name of iso-image>.iso -boot c" to boot ReactOS from "ros_hdd01.img" with your cd as drive d

*) I use this batchfile:
SET IMG="ros_hdd01.img"
IF NOT EXIST %IMG% qemu-img.exe create %IMG% 2048M
**) Or: Copy this string, right-click into the commandshell, then choose "Paste".
***) This works fine - you don't need to think about it, but for more info please read QEMU's documentation, starting with the readme - files

What did i use trying this?
- QEMU for Windows 0.9.0 (
- ReactOS from svn (bootcd-30952-dbg.iso)
- Windows XP Prof SP2

Post Reply

Who is online

Users browsing this forum: Yeti [Bot] and 1 guest