IF ALL LINKS ARE DOWN:
You can google the SHA-256 hash and download it from anywhere, then verify the SHA-256 with 7zip to make sure it hasn't been tampered with.


Windows 10 IoT Enterprise LTSC 21H2:
Filename: en-us_windows_10_iot_enterprise_ltsc_2021_x64_dvd_257ad90f.iso
SHA-256: A0334F31EA7A3E6932B9AD7206608248F0BD40698BFB8FC65F14FC5E4976C160
SHA-256 Source (MS account required to view SHA, subscription required for downloads):
https://my.visualstudio.com/Downloads
Download: https://massgrave.dev/windows_ltsc_links.html
Activation: https://github.com/massgravel/Microsoft-Activation-Scripts/archive/refs/heads/master.zip


Windows 11 IoT Enterprise LTSC 24H2:
Filename: en-us_windows_11_iot_enterprise_ltsc_2024_x64_dvd_f6b14814.iso
SHA-256: 4F59662A96FC1DA48C1B415D6C369D08AF55DDD64E8F1C84E0166D9E50405D7A
SHA-256 Source (MS account required to view SHA, subscription required for downloads):
https://my.visualstudio.com/Downloads
Download: https://massgrave.dev/windows_ltsc_links.html
Activation: https://github.com/massgravel/Microsoft-Activation-Scripts/archive/refs/heads/master.zip



Always verify SHA with 7zip for non-MS sources.
It's best practice to verify SHA from multiple sources to ensure they match and not trust only a single source.
Some of these databases scrape VisualStudio themselves, and others just scrape from other scrapers.
 

SHA Databases:
https://my.visualstudio.com/downloads (Account required to search/view SHA)

https://www.heidoc.net/php/myvsdump.php (CA, USA)
https://www.whois.com/whois/heidoc.net
 
https://dnhash.net (NC, USA)
https://www.whois.com/whois/dnhash.net
 
https://msdn.su (Russia)
https://www.whois.com/whois/msdn.su
 
https://files.rg-adguard.net/category (Russia)
https://www.whois.com/whois/rg-adguard.net


 
======= Verify SHA-256 with 7zip =======
https://www.7-zip.org/download.html
Install 7zip > right click ISO > CRC SHA > SHA-256
If the SHA-256 matches the one from visualstudio.com, then the file has not been tampered with since its official release.