If you are looking for an official Microsoft download page for "Windows Installer 5.0 for Windows 10 64-bit," you will not find one. Instead, use these official resources:
Historically, older versions like Windows Installer 4.5 or 3.1 were released as independent standalone redistributable software packages that users could download manually to upgrade legacy operating systems like Windows XP or Windows Vista. Windows Installer 5.0 Download For Windows 10 64-bit
This is a common error. Follow the troubleshooting steps above, specifically Step 2 (Re-register the service) and Step 3 (Run SFC/DISM) . Ensure you are running the Command Prompt as an administrator. If you are looking for an official Microsoft
For very specific version requirements (e.g., a build server needing an older 5.0 patch), you can search the Microsoft Update Catalog for terms like: Follow the troubleshooting steps above, specifically Step 2
Microsoft historically provided redistributable installer packages for previous versions:
No legitimate standalone installer exists for Windows 10 64-bit.
Windows Installer 5.0 Download for Windows 10 64-bit: Everything You Need to Know