These are pre-cracked folders that don't require an install.
Developed by Systemax Software, Sai 2 is the massive update to the original Paint Tool Sai. It isn't just a patch; it’s a complete overhaul that includes: Paint Tool Sai 2 Free Download Full Version Deviantart
Cracked versions are notorious for crashing, and because they are unofficial, you cannot get support from Systemax. The "Technical" Free Way (The Official Preview) These are pre-cracked folders that don't require an install