Beware if you want to use cy-GB locale on Windows Server 2003 - you will need to update to Service Pack 2 - as this locale is not present in the original release or service pack 1.
If you cannot upgrade to service pack 2, I found a useful resource on the University of Wales - Bangor - language technology website.
I have repeated the relevant information here for future reference:
1. Create a cy-gb.ldml with the C# code by running the following code on a windows XP SP2 machine (NB this references the following Sample code for getting ELK cultures on other platforms by Michael Kaplan).
2. Copy the cy-gb.ldml file to your Windows 2003 (or Windows 2000) machine
3. Open the cy-gb.ldml file in Notepad or any text editor and search for the lines containing :
and change them to
Then register your new ‘custom locale’ by executing the following code on the Windows 2003 box:
NB - to compile the code you can use the following:
So should all be okay now!!