gedit text display

[Thomas Blasejewicz]

I am using Ubuntu 9.04, Japanese localized version.
Using the text editor "gedit" I can write new text in the three
languages I am using:
English, German + Japanese.
Displays fine.

Yet, after transferring a text file (created with a text editor in
Windows) either by copying the file
via floppy or else sending it by mail, I get a lot of wrong characters.
Not only do the Japanese character not display, but also something like
quotation marks too are garbled.

Is there anywhere a setting, where I can change text encoding to get the
display right?
Or is there any other trick?

Thank you.