Language setting / Depend on OS default?

Language setting / Depend on OS default?

How to change the language setting?

I want to have my invoices in English but the language setting has been changed since last time I issued an invoice in the end of Jun. Now the language is same as my PC OS language. I like this type of kindness but I want to have them in English.

I searched in Invoice Forums/Help/Blogs but I could not find any tips.

Tamopy