You are not able to edit the file as it does not "belong" to you.
Open a terminal window and enter the following command:
ls -Al /etc/speedtouch.conf (that's a capital "A" and lowercase "ell")
I get this:
-rw-r--r-- 1 root root 530 Feb 10 2003 /etc/speedtouch.conf
Which tells me the file is owned by "root", and not writeable by others.
So you must be root to edit this file. Type this command:
and give the password.
Now you are root and can edit and save the file. I use vi as my editor, but there are others that are supposed to be easier. To use vi, enter the following command:
The file opens. Use the cursor keys to navigate to where you want to edit.
Press the i key on your keyboard to insert text. Now you may type text and use the backspace and delete keys.
When you have finished editing press Escape key, then colon key (
then w to WRITE the changes, then q to QUIT the editor.
If you mess up just press Escape, :q! to quit without saving changes.
Being "root" is dangerous, you can mess things up big time, so once you have edited the file type the command
You are then back as yourself, a regular user.
Hope this helps.