can't open .txt file from Windows Explorer

When I click on any .txt file in Explorer I get error message:

C:\My
Cannot find this file
Please verify that the correct path and filename are given

The C:\My is supposed to be C:\My Documents\File folder\file.txt.
If this is the problem how can I change the C:\My to C:\My Documents?
In Explorer when I right click on the filename and choose Properties the
dialog box shows the proper Location: C:\My Documents\File folder\File so
apparently the proper information is in the file details.

The files being opened are .txt files being opened with WordPad.