Sounds like a corrupt FAT table.

Try backing up the entire drive (on a sector by sector rather than file basis if you can, i.e.: an immage backup) and then try running scan disk.

Check below link it will be helpful to you

http://www.filerepairforum.com/forum/databases/databases-aa/dbase-iv-clipper-foxpro/689-corrupted-dbf-file-what-to-do

Or use the special program DBF Fix Toolbox http://www.dbf.fixtoolbox.com/[/url]