Follow these steps
1
Use another working PC to download the official Windows 11 Media Creation Tool from Microsoft.
2
Insert an empty 8 GB or larger USB drive and use the tool to create installation media.
3
Back up documents, browser passwords and activation details from the target PC.
4
Restart the PC and open its boot menu (often F12, Esc, F9 or F11), then select the USB drive.
5
Choose language and keyboard, select Install now, then choose Custom installation.
6
Select the correct Windows drive carefully; delete partitions only if you already backed up everything.
7
After setup, connect to the internet, run Windows Update and install the official device drivers.