>Don't understand this.

Ok, you know how the Copy File routine worked? Instead of moving the whole file at once you moved parts of it and incremented a progress bar in the middle? Well, do the same thing here. If you've got 5 million records, use FGETS() to get the first 50,000 records into a new file and append that, then the next 50k, then the next 5k, ect. ect.