After using Linux for about three months, I decided to return to Windows. Unfortunately, I installed Linux without setting up dual boot, and now the Windows installer keeps failing. I already disabled Secure Boot, but I keep getting stuck in the Ventoy and Lenovo boot menus. What is the correct way to create the Windows installer and prepare the laptop's drive for a fresh installation?
3 Answers
This sounds recoverable; the laptop is very unlikely to be permanently damaged. The important steps are to make the installation USB correctly, select it from the Lenovo boot menu, and use the Windows installer’s custom disk setup. If the USB does not boot properly, recreate it with Microsoft’s official media creation tool rather than only copying an ISO file onto the drive.
Create a proper bootable Windows USB using another computer, then boot the Lenovo from that USB. You may want to re-enable Secure Boot before trying the Windows installer, since Windows supports it. In the installer, choose a custom installation and remove the existing Linux partitions if you are sure you no longer need the data. Windows can then create the required partitions automatically.
The Windows installer may be failing because the disk is currently divided into Linux partitions, such as ext4, which Windows does not use for its system installation. Boot into the Windows installer, select the custom installation option, and delete the Linux partitions on the target drive. Be very careful to back up anything important first, because deleting them erases the data. After the drive shows as unallocated space, let Windows create the partitions itself.
How do I remove or repartition those Linux partitions?
So I should download a Windows ISO or installer onto a USB using another device, then boot the laptop from that USB?