dftf
If you run an older version, remember you won’t get any Windows Updates past a certain point.
Download the Media Creation Tool for the version you want from the links below — it will let you create an ISO image (which you can burn to a DVD, or use to install inside a virtual-machine) or a bootable USB drive (the drive must be 8GB or larger, and everything will get deleted off it in the process, so check there’s nothing you need to keep first!).
The links:
20H2:
download.microsoft.com/download/4/c/c/4cc6c15c-75a5-4d1b-a3fe-140a5e09c9ff/MediaCreationTool20H2.exe
2004:
software-download.microsoft.com/download/pr/8d71966f-05fd-4d64-900b-f49135257fa5/MediaCreationTool2004.exe
1909:
download.microsoft.com/download/c/0/b/c0b2b254-54f1-42de-bfe5-82effe499ee0/MediaCreationTool1909.exe
1903:
download.microsoft.com/download/9/8/8/9886d5ac-8d7c-4570-a3af-e887ce89cf65/MediaCreationTool1903.exe
1809:
software-download.microsoft.com/download/pr/MediaCreationTool1809.exe
1803:
software-download.microsoft.com/download/pr/MediaCreationTool1803.exe
1703:
download.microsoft.com/download/1/F/E/1FE453BE-89E0-4B6D-8FF8-35B8FA35EC3F/MediaCreationTool.exe
1607:
download.microsoft.com/download/C/F/9/CF9862F9-3D22-4811-99E7-68CE3327DAE6/MediaCreationTool.exe
1511:
download.microsoft.com/download/1/C/4/1C41BC6B-F8AB-403B-B04E-C96ED6047488/MediaCreationTool.exe
1507 (use the first link if you want 64-bit Windows 10, the second for 32-bit Windows 10 — in all later Media Creation tools, you can choose inside the tool itself which “bit” you want):
download.microsoft.com/download/1/C/8/1C8BAF5C-9B7E-44FB-A90A-F58590B5DF7B/v2.0/MediaCreationToolx64.exe
download.microsoft.com/download/1/C/8/1C8BAF5C-9B7E-44FB-A90A-F58590B5DF7B/v2.0/MediaCreationTool.exe