Hjsplit

Separate and re-join files of all types.
Tutorial HJ-Split
Whenever you download a movie or game in more parts and it contains extensions: 001, 002, 003 and so on, you will use HJ-Split to join them.
Download the program hjsplit
Here is a step by step

1. Keep all parts in one folder.
2. Make sure that all have the same name, only changing the extension.
3. Double click on the icon of the program.
4. Click Join

5.Click in Input File

6. Follow the ABC
Look for the folder where the files are
Select the file to end .001 (the rest will not appear)
Click in Open.

7. Click in Start

8.Wait for the bar reaches the end and ready to use the file may exclude parts.

Video: How to use HJsplit