Windows error 0xC0000005 is an access violation error meaning a program tried to access memory it's not allowed to use. Here's how to fix it.
The program has a memory access bug or is incompatible with your system configuration.
Next step: Update the program to the latest version. If it's an older game or app, right-click → Properties → Compatibility and try 'Run this program in compatibility mode'.
Antivirus is blocking the installer from accessing memory it needs.
Next step: Temporarily disable your antivirus real-time protection, run the install, then re-enable protection. Only do this for installers from trusted official sources.
RAM is failing or a driver has a bug that causes illegal memory access.
Next step: Run Windows Memory Diagnostic (search it in Start → 'Restart now and check for problems'). Also update all drivers, especially your GPU and chipset drivers.