Gedit has a very annoying habit after downloading, it autamatically takes the default language Windows is set to (in my case it’s Dutch). Changing the default language to English is for some mysterious reason, not possible through the menu of gedit (Tools, Set Language).
This is what you get when you try to change it through the menu:
Don’t worry though, it is possible to change your language into English, just copy and paste this path into your file browser (close gedit first!):
You’ll get this screen:
Here you select the folder that is named after the country code of the language gedit automatically sets to, as you can see in my case its “nl”. Delete this folder, open gedit. Et voilà, it opens in English. This solution was tested in Windows Vista.