Computer/workstation may have installed too many software packages, so the environment path or system path variable is too long and has exceeded the windows limit of the length of path variable characters. Therefore Statistica is not able to add its path to the system path variable. 

Check the Limitation to the length of the system PATH variable in windows systems: Here

WORKAROUND:

Go to Control Panel | System | Advanced Settings | Environment Variables, where you can view and edit all path variables.

If the system path is too long exceeding the windows limit, the user may need to remove some unnecessary or not-in-use or previous uninstalled software paths from the PATH environment variable.

Proceed with caution here, as removing certain paths will break the system. There also needs to be room for the Statistica install path and C:\WebSTATISTICAPub\wwwroot\PHP (if it’s a WebStatistica install). If either of these paths already exists, they should not be removed.

It's recommended that the user back up the PATH environment variable string (copy and paste to a text file) before changing it. 

After editing the system path variable, restart the system for the change to take effect. Then try re-install/upgrade Statistica.