Hi Guys, Thanks for all the comments. Just one or two other things: 1. I can not write the file in one shot, as the files are 250MB in size. I can not allocate 250MB to write to a file, there is just not enough ram. 2. We've found FAT32 wholly unsuitable for big partitions (120GB and up). FAT32 does not even format reliably on these big partitions. Cheers OD