Windows 7 Icon Pack — By 2013 Windows 8.1 ((exclusive))

Bringing Back the Glow: The Windows 7 Icon Pack for Windows 8.1

Ten most-downloaded Windows 7 Icon Packs on DeviantArt and Softpedia between October 2013 and December 2013.
Technical patch notes from tools like 7Conifier and Resource Hacker.
Forum threads on Reddit’s r/windows8, MDL (My Digital Life), and TenForums.

.msstyles and resource ID differences: Windows 8/8.1 themes and style files use different image indices and sometimes different resource layouts, so 1:1 theme transfer rarely works without modification.
Shell and icon caching: Windows maintains icon caches (iconcache.db) and thumbnail caches that must be rebuilt after changes.
System file protection and unsigned theme limitations: By default, Windows blocks unsigned visual style files and direct modification of system files; theme patchers or service-based approaches are used to allow custom themes.
32-bit vs 64-bit resource differences: Some packs provided separate resources for x86 and x64 systems.
UAC and permissions: Many installers require elevation and may change file permissions (takeown/icacls) to overwrite protected resources.

Security Warning: Modern analysis from security platforms like ANY.RUN has flagged this specific file for malicious activity. It was found to check system languages, read machine GUIDs, and modify system files—common indicators of trojans or adware from that period. Windows 7 Icon Pack By 2013 Windows 8.1

IconPackager 10 (Stardock): They have a "Windows 7 Classic" pack that is modernized.
7TSP (2019 Edition): Some developers ported the old 2013 assets to work with Windows 10 v1909. (Check their Discord—do not use the original 2013 .exe files).
Manual Replacement: You can download the .ico files from the original 2013 pack (extract them using 7-Zip), right-click your desktop shortcuts, and change the icon manually. It is tedious, but safe.