I am not sure about this but if you mean you purchased an Acer Laptop and
received a Vista disc via upgrade redemption then i know you can only have
the language which was on your previous OS and where you bought it from.
Another words you bought the laptop in Netherlands and you received an
upgrade disc via the upgrade redemption program and the language will be the
same as previous OS.
That is if you had vista via upgrade redemption.
Go to this link
http://global.acer.com/support/winvista/index.htm
Half way down the page you will see this:
Notes:
1.You may only redeem the same language upgrade as that which was originally
purchased.
2. The Windows Vista™ upgrade process depends on the Windows® XP edition and
language you currently have on your computer. For details, please click here
(It is in very small writing, and in sort of a grey colour)