User is unable to upgrade Statistica when he has installed a foreign language version of Statistica with an English license.
For example, user has a license for English version of Statistica (e.g. 13.0 English), but he has used it to install a French version of Statistica (13.0 French). Though the English license have passed through the installation of the French version, the installed French version would give problem when it comes to upgrading to a higher version in future. Neither the higher version of French installer (e.g. 13.3 French installer) nor English installer (13.3 English installer) could detect the existing French version (e.g. 13.0 French) installed. Due to this reason, the user is unable to upgrade his Statistica. 

User has problem upgrading Statistica when he has installed a foreign language version of Statistica with an English license.

Windows 7, Windows Server 2012 R2

Installing or Upgrading across different language packs of Statistica has not been officially tested thoroughly. Therefore, user is suggested to install the right language pack of Statistica based on the license purchased, i.e. install English version of Statistica if the license purchased is for English version, and install French version of Statistica if the license purchased is for French version. This is to avoid possible upgrading problem in future. 

To resolve such upgrading problem raised from, for example, installation of foreign language Statistica with an English license, user would need to 
1. Uninstall the existing foreign language version of Statistica installed (e.g. 13.0 French)
2. Re-install the appropriate English version of Statistica with his English license (e.g. 13.0 English)
3. Upgrade the reinstalled English version (13.0 English) using a higher version of English installer (e.g. 13.3 English installer)