If you get a "file not found" type error opening a table, you've probably got hard coded paths in the DDFs.
Do you get results if you double click on the "X$FILE" table in the Pervasive Control Center? If so, check the table you are trying to open that gives the error and look at the "XF$LOC" field. Does it have just a file name or does it have a path and file name? If it's got a path and file name, you'll need to make sure the DDF and the data files are in the proper paths. ANother option would be to copy the DDFs and data files to another directory and remove the paths from the DDFs. You can do that using the PCC manually or you can use a third party tool (like my DDF Path Fixer at
http://www.mirtheil.com/pathfixer.asp).