I think you are using Inno Setup for creating the Windows installer?
I have translated this into Scottish Gaelic. Copy [font=courier]ScotsGaelic.isl[/font] to [font=courier]C:\Program Files (x86)\Inno Setup 5\Languages[/font], then add the following line to the .[font=courier]iss[/font] file:
Inno Setup.zip (11.3 KB)