Hi, I have been trying to merge two large .avi files and in order to do it, I used the following script: M:\2008_07_Holiday>copy/b A.avi + B.avi Holiday Full.avi The process takes about the same time for both files (as it is logical given they are about 13 GB each), so I get a single file of 26GB and a message: A.avi B.avi 1 file(s) copied. The problem is when I try to play the whole thing with WMP11 or any other reader: there is only file A.avi even if the file size is 26 GB. In doubt, I tried the process several times, also adding /b after B.avi, but the result never changed. Is there a limit in file size in DOS?? Or, is their something wrong in my script given that I am not a DOS expert? Thank you Alex AOPEN AX34, P3 1.0 GHz, 1GB RAM, HD WD 120 GB, LaCie 500 GB, Plextor 16/10/40A, Plextor PX-716A, HIS Excalibur Radeon 9600 256Mb, 2xMonitor Philips 109P20, Canon i865, Philips ToUCam Pro, WXP PRO SP3

Why not use a free avi joiner program? http://www.dirfile.com/kate_s_video... Before posting try google. Backup. Use anti virus software.

Well, usually I do it with VirtualDub, but this time the final result is not as good as it should, that's why I am trying DOS. However, I'd like to know if there is a specific reason why I cannot achieve the expected result in DOS. Thanks Alex AOPEN AX34, P3 1.0 GHz, 1GB RAM, HD WD 120 GB, LaCie 500 GB, Plextor 16/10/40A, Plextor PX-716A, HIS Excalibur Radeon 9600 256Mb, 2xMonitor Philips 109P20, Canon i865, Philips ToUCam Pro, WXP PRO SP3

Some files have some header info at the beginning of the files, like it's 'length' for instance. That's why you have to use a video joiner. It will correct the header info.