# Setting Guest OS Type and Version

You can change which guest OS a virtual machine is configured to work with. You need to change it in the following cases:

* If you upgrade the guest operating system (for example, from Windows 10 to Windows 11), you need to change the guest OS type and version correspondingly, or [Parallels Tools](https://docs.parallels.com/landing/pdfm-ug/v20-en-us/parallels-desktop-for-mac-20-users-guide/advanced-topics/installing-and-updating-parallels-tools) may start working incorrectly.
* If you create a virtual machine without installing an operating system, and then decide to use it with a different operating system than the one you initially specified.

To set the guest OS type and version:

1. [Shut down the virtual machine](https://docs.parallels.com/landing/pdfm-ug/v20-en-us/parallels-desktop-for-mac-20-users-guide/use-windows-on-your-mac/getting-started/shutdown-and-suspend-windows).
2. Open the **Actions** menu and choose **Configure**.
3. Click **General** and select an OS from the menu just above the **Name** field.