This code is exiting before it ever gets to the drive mappings, surely? I'm not entirely together at the moment, but I would suggest that what you're doing is:

1) Checking the country code (presumably 00000409 is the US code Windows defaults to)
2) If it is this default code, changing it, and if the change is successful, coming back to check it again.
3) Once the code is not reading 00000409, you are announcing that it is set to UK, and exiting the script.

You should probably try something like this:

code:

---

If ReadValue("HKEY_CURRENT_USER\Control Panel\International", "Locale") <> "00000809" ;ie not UK
   $x = WriteValue("HKEY_CURRENT_USER\Control Panel\International", "Locale", "00000809", "REG_SZ")
   If $x = 0
      ? "Locale set to UK."
   Else
      ? "Couldn't set locale."
      Exit
   Endif
Endif
...
;script continues...  

---

HTH