The safest way to get the ISO is directly from Microsoft's servers. Microsoft no longer lists VS2010 SP1 on the front-facing Visual Studio download page. You must use the "My Visual Studio" portal or the direct archive link.
Remember: The ISO is just a starting point. Maintain a documented build environment (Docker or VM snapshot) so you never have to hunt for it again. visual studio 2010 sp1 iso
: Microsoft recommends using the File Checksum Integrity Verifier to check the ISO's SHA1 hash before burning or mounting it to prevent installation corruption. The safest way to get the ISO is