.001 file, like .002 file, .003 file, and other similar files, is a separate file which contains the components of part of a program. These files need to be joined together and reverted to the original file when put into use. To achieve this goal, the user should keep to the following steps:
1 Download 7-Zip and launch 7z457.exe to install the program
2 Right-click the .001 file and choose 7-Zip>Extract Here
3 Apply the same approach to other files, following the sequence from .001 to .009.
In most cases, restoring of the separate files will end up with an ISO or Bin file. Sometimes, it will also end up in an installation directory for the program ready to run.