There are legitimate reasons why some users look for these specific legacy versions:

This indicates that the host computer lacks the legacy libraries required to decode the C++ code used to build CS5.

Adobe Illustrator CS5 Portable: The High Risks and Modern Alternatives

Right-click the Illustrator portable .exe file and select Properties . Go to the Compatibility tab. Check "Run this program in compatibility mode for" and select Windows 7 . Additionally, check the box for "Run this program as an administrator." Click Apply and restart the app. Error: "Missing MSVCP100.dll" or "Runtime Error"