First possibility:
- You have to check the catalog properties (Open the .po file in POedit program then choose Menu 'Catalog'->'Properties' or simply just Alt+Enter, and check the Sources Path
- Check the base path is correct refer to C:\Users\HS\SkyDrive\Webkodning\wamp\www\test\
- Make sure youu already add "." (without quotes) in paths
Second possibility:
When you test the code use the lower string parameter for locale (de_de not de_DE) like this htttp:\url\test.php?locale=de_de
Third possibility:
Make sure poedit already generate the .mo file and if it's already then try to restart your WAMP server
Hopefully it will help