d_touch -
Can you be more specific about what happens when you try to login from your English OS? Does it give you an error? Does it just not log you in?
I don't think it has to do with the language of the OS, but I think it may have to do with your internet browser settings. Can you let us know what browser you are using and if you are able to accept cookies?
Can you login at ni.com/profile using your English OS?
Thanks!
Molly K.
Web Support & Operations Manager
National Instruments