You can use keys across languages, but remember that if it's an original Polish license and you download via the Norton Download Manager dialog, you will automatically get the Polish version again. If it's an original English license, you get the English version.
But if you don't know, there is a circumvention :
1. download the English version from here :
www.norton.com/nis11
2. Download the Norton Removal Tool from here :
www.norton.com/symnrt
2. go to Programs and Features and uninstall NIS.
3. run the downlaoded Norton Removal Tool, in case there are language incompatibilities and reboot
Note : NRT will dlete all your Norton programs, so you also will have to reinstall them all.
You can try to leave this step out, if you do not want to install the other programs again.
4. Install the downloaded English version of NIS. The key will still be on your system, so the days left should appear in your Norton main screen.
You can always save your key from here, before uninstall :
C:\ProgramData\Norton\00000082
In one of the subdirectories (choose the latest created) there is a file 'key.txt'.
Next time you buy Norton, buy the English version (Delphinium can help you with some deals); only enter your key and all is ok.
Do not extend your subscription with Norton, as then the key of the oroigonak version is extended.