Start with the computer you will boot
Write down which operating system and architecture the destination computer needs. Check whether its firmware is configured for UEFI or legacy BIOS boot. Those details determine the image and target settings; the Windows computer doing the preparation does not have to be the machine that will eventually use the USB. Obtain the ISO from the operating system publisher and keep its version identifiable.
If the image is somewhere in a crowded download folder, Everything can search for its filename. Confirm the actual file, edition and architecture afterward. Search results do not authenticate an ISO. Where the publisher provides a checksum, compare it using an appropriate verification method before making installation media.
Protect the files already on the USB
Choose a stick with enough capacity for the selected image. Copy anything you need from it to another storage device and check that the copies open. Creating bootable media with Rufus normally formats the destination and removes its contents. A second partition or a familiar volume label is not a substitute for verifying which physical drive you selected.
Disconnect unrelated removable drives if their names are similar. Download the appropriate Rufus executable from its official page and run it on supported Windows. Review the publisher before approving administrator access. The application does not need a conventional installation wizard; you still need to select the destination carefully.
Load the image and verify the proposed settings
Select the intended device in Rufus, checking both name and capacity. Load the ISO and review the proposed partition scheme and target system. GPT with UEFI is common on modern machines; a legacy BIOS target can require a different choice. Use the destination computer's requirements rather than changing settings simply to match a random tutorial.
Read the erase warning before starting. Keep the USB connected and the computer powered until completion. Do not begin another write task on the same stick. A completed progress bar means the media creation finished, not that the operating system will support every component in the destination PC.
Test the result before depending on it
Safely eject the stick, connect it to the target and select it from that computer's boot menu. Confirm that the expected installer or recovery environment opens before proceeding with installation. Merely testing the boot menu does not require deleting the internal disk.
If the USB is absent, recheck firmware mode, image architecture and the selected boot entry. Avoid changing multiple unfamiliar firmware options at once. Keep your original ISO and backups until you have verified the medium and finished the intended work.
For several boot images on one drive, consider Ventoy: after its initial USB setup, compatible ISO files can be copied onto the data partition. That first setup can erase existing files, so check the target carefully. balenaEtcher instead writes suitable disk images directly; it is not the usual choice for turning a standard Windows installation ISO into a working installer.
