Hi guys For a science fair project, I am going to test the effects of X-radiation on flash memory. I'm intending to fill a number of 16MB (15,876,096 byte) Compactflash cards with data, hash check the data with hkSFV, expose them to the radiation and hash check again for any data corruption. The flash cards have a block size of 4KiB. To make the hash checking more 'accurate', I'd like to use many files which are as small as possible - this would be 3876 files of 4KiB each. However, I'm struggling to actually get 3876 4KiB files on a card, or onto my hard disk. It's easy enough to make a 4KiB file, just open notepad and write 4096 1s. I can't figure out how to make 3875 copies of this file though. If I use copy+paste in Windows XP, I get a 'disk is full or write-protected' error after about 1375 files, every time. I think it's a naming problem - I can never get above 'Copy of (999) file.txt'. I think this could be done much better with a batch file. However my batch file writing skills are limited. Could anyone advise me on how to write a batch file which copies a file called 1.txt n times, with the filenames as 1+n.txt?