if you are not a beginner....you may try this if above fails
source.....
http://www.debian.org/doc/manuals/us...en.html#s-ctkm
13.6.2.1 Changing the Command Line Keyboard Mapping
1. Logged in as root user, type: dpkg-reconfigure console-data.
2. Answer the questions on the screen as they appear.
13.6.2.2 Changing the Desktop Keyboard Mapping
1. Check that the keyboard mapping that you want is installed in / usr/shre/keymaps/i386.
If it is not, then install the package before remapping.
2. Open /etc/X11/XF86Config-4 in a text editor.
3. Find the "Input Device" Section, then the Identifier "Generic Keyboard."
4. Edit the option "XkbLayout".
The default setting for "XkbLayout" is "us".
However, you can change this setting using any layout listed in / usr/share/keymap/i386. The setting must be enclosed in double quotation marks.
5. Restart your system, or restart the X Window System. The X Window System is now configured to use the new keyboard mapping