.001 & .002 files are essentially a partial download of a much larger file. There are several different reasons why the up-loader of the file may have chosen to split the file into different sections, but typically you see these files when the original file up-loader is encountering upload restrictions of some sort. It’s not as neat as a single .zip or .rar file, but no need to fret, it only takes a minute to use HJ-Split and merge all of these part files back into a usable file type 😀
1.) Download the latest version of HJ-Split @ hjsplit.org
2.) Unzip/extract the .zip download. Then simply run the resulting hjsplit.exe file to start HJ-Split.
3.) Click the Join option at the HJ-Split menu.
4.) Then select Input File:, then browse to your .001 file you wish to join/merge.
5.) Lastly, Click Start to begin the merge process. You should then be greeted by a new window that will track the progress of the Join job.
That is all there is to it! Enjoy~