> For the complete documentation index, see [llms.txt](https://support.onlogic.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.onlogic.com/support-articles/how-tos/firmware-bios-drivers/creating-a-ms-dos-bootable-flash-drive.md).

# Creating a MS-DOS bootable flash drive

Booting MS-DOS from a USB drive can be useful for applying BIOS updates and other tasks.

### <mark style="color:blue;">Required Tools</mark> <a href="#required-tools" id="required-tools"></a>

* USB flash drive (32GB or smaller)
* A Windows 7/10 PC

### <mark style="color:blue;">Creating the drive</mark> <a href="#creating-the-drive" id="creating-the-drive"></a>

<figure><img src="/files/Y4aC2GAiHpC5tdv0yDLT" alt="" height="100" width="88"><figcaption></figcaption></figure>

* Download the Rufus tool from [rufus.ie](https://rufus.ie/)

<figure><img src="/files/wm5lpP6HhUUcubf23Zvy" alt="" height="218" width="474"><figcaption></figcaption></figure>

* Launch Rufus
* Under “Device” select your USB drive
* Under “Boot selection” choose “FreeDOS”

<figure><img src="/files/zB9wEMljZAe5b4CbYnyf" alt="" height="153" width="470"><figcaption></figcaption></figure>

* Click START at the bottom of the window

<figure><img src="/files/f53icsF1x5jm5WAZpBOa" alt="" height="168" width="408"><figcaption></figcaption></figure>

* Double check you have selected the correct drive and press OK to proceed

<figure><img src="/files/1vkReASSQogAGrINAyar" alt="" height="74" width="461"><figcaption></figcaption></figure>

* When the status bar says READY, the process is complete

<figure><img src="/files/xtranAcwJtrFLwsfK8NB" alt="" height="361" width="445"><figcaption></figcaption></figure>

* Copy any files you will need in DOS to the flash drive. If you are applying a BIOS update, copy those files now.
* Eject and unplug the flash drive

### <mark style="color:blue;">Booting to the drive</mark> <a href="#booting-to-the-drive" id="booting-to-the-drive"></a>

<figure><img src="/files/PLfRkZi5BI5MHcWENUns" alt="" height="335" width="466"><figcaption></figcaption></figure>

* Connect the flash drive to the target PC and power it on. Go into the BIOS (Typically F2/Del/Esc) and set it as the primary boot device.
* On newer systems, it is necessary to enable CSM / legacy boot mode as shown.

<figure><img src="/files/STuEKneM1tqbyxgejEtw" alt="" height="418" width="566"><figcaption></figcaption></figure>

* If successful, you will be greeted with the familiar old DOS prompt.
* Use the dir command to confirm what files are on your USB drive.
* Update .bat files can be executed by typing the filename.