We will permanently drop support for targeting Windows 7 and Server 2008 R2, plus Windows 8.1 and Server 2012 R2. This time, we've got ultraboss approval (internal "experiences" VSO-2164004 and VSO-2441848).

⚙️ Code Changes

• Win8 baseline: Drop support for Win7 / Server 2008 R2 #5432
  • This cleanly reverted Temporarily restore support for Win7 / Server 2008 R2 #4857 which partially reverted Drop support for Win7 / Server 2008 R2 #4742.
  • Followup: stl/CMakeLists.txt: Remove redundant Synchronization.lib #5496
• Win8 baseline: Improve STL Hardening codegen size #5433
  • Followup: RWC workaround: Use __builtin_trap for ancient Clang #5458
• Win8 baseline: Simplify <filesystem> API calls #5434
• Win10 baseline: Drop support for Win8.1 / Server 2012 R2 #5510
• MSVC-PR-631778
  • NON-GitHub: Link src/vctools/PDB binaries against synchronization.lib.
  • NON-GitHub: Update the VCRedist to require Win8.
  • NON-GitHub: MSVC.Setup.Redist.UCRT.XP was already dead.
  • NON-GitHub: Remove the Vista MSUs (already dead) and Win7 MSUs.
• MSVC-PR-637104
  • NON-GitHub: Remove redundant Synchronization.lib.
  • NON-GitHub: Update the VCRedist to (try to) require Win10.
  • NON-GitHub: Delete the UCRT MSUs.
    • This shrinks the VCRedist by 6.7 MB. (24.4 MB => 17.7 MB for x64; 13.3 MB => 6.6 MB for x86)

📑 VS/MSVC Documentation

• Document this in the release notes.
  • I've sent suggested wording to Sy Brand: "Visual C++ no longer supports targeting Windows 7 / Server 2008 R2, Windows 8 / Server 2012, and Windows 8.1 / Server 2012 R2. The minimum supported operating systems are Windows 10 / Server 2016."
• Document this on the https://aka.ms/vcredist page.
• Write a C++ Team Blog post.