If you cannot or do not want to use a USB drive, several alternatives are available depending on your current system's status:
If you are planning a project involving a PC build or a fresh start, do yourself a favor: buy an 8GB (or larger) USB flash drive. It is the cheapest, most reliable tool in your tech arsenal. do you need a flash drive to install windows
This is the official Microsoft method for users who want to reinstall or upgrade while their current system is still functional. If you cannot or do not want to
For Windows 10/11, an 8 GB USB drive is the minimum; 16 GB is safer. do you need a flash drive to install windows
There are two specific scenarios where you cannot install Windows without a USB drive (or a DVD/external drive).