Hello,
After you uninstall the Spanish version of Advance Steel, please go to the folder : C:\ProgramData\Graitec\AdvanceSteel\ (for Windows Vista and Windows 7)
C:\Document and Settings\All Users\Application Data\Graitec\Advance Steel\ (for Windows 2000 and Windows XP)
and delete the folder : "2010" located here.
After this, install the english version.
Best Regards,
Dumitru Berteanu.