This blogs topic is about How to split and combine large files using 7-Zip. This is an important scenario in case file size is too big to be copied over the network, or too big to fit in USB drive. By using the split technic, we can divide the big file into smaller chunks which can be easily copied to the destination location, and further can be combined to reform the original file.

Download and install 7-Zip

To split the file, you need one of the software’s which has feature to split the files. 7-zip is the freeware which can be downloaded and installed to perform this task. Another benefit of 7-zip is, once installed you can take copy of source from C:\Program Files\7-Zip (64-bit version) and use it any destination system without installing it. 7-zip is available for both 64 bit and 32-bit OS architecture.

Split the file

For demonstration purpose, I am going to use c:\temp\boot.iso file which has a file size of approximately 400 MB.

Once 7-Zip application is installed, launch it by clicking on start menu, you will be able to 7-Zip File Manager.

In navigation pane, type c:\temp to navigate to boot.iso file location. You will be able to see Boot.iso properties such as name and Size.

Right click Boot.iso and select Split File, this will open a new window asking location of the file to Split to, along with Split to volumes, bytes.

By default value is 10M (ie 10 MB), lets select option 100MB from the drop down menu to have 4 or 5 files, and click on OK.

We can now see 5 files have been created starting from Boot.iso.001 to Boot.iso.005 having 100 MB file size for first 4 files and last file with 2 MB file fize.

Copy split files to destination location

As we have already split the files, this is the time to copy the split files to destination location. Copy all 5 files as all of them is required to create a final file which is equivalent to our original file Boot.iso.

I have copied the files from c:\temp to c:\backup folder as shown below.

Combine files using 7-Zip File Manager

Launch 7-Zip File Manager, navigate to c:\backup to view all split files. Right click Boot.iso.001 and select Combine files. Make sure to only select first split file or else you will be getting error Can not detect file as split file.

Popup window will appear asking the location to Combine to along with all 5 files showing which will be used to join to form the final file, click on OK to generate boot.iso file with same file size which we saw previously under c:\backup location.

Split files Boot.iso.001 to Boot.iso.005 are ready to be deleted as these are no longer required.