How to open .001 files: .001, .002, .003, .004 etc.
These files are "split" and contain separate components or parts of a program and need to be "joined" back together in order for the application to work, these parts will end up creating an ISO or Bin file.

In other cases, the parts will end up making a directory that houses an installation directory for the program, or the entire program in ready to run form.

The file ending with .001 extension contains the information that will open and "join" the rest of the .002, .003, .003, .004 files together.

Use 7-Zip. 7-Zip is a well known Free archiving tool.

What is 7-Zip?
7-Zip is free software with open source. The most of the code is under the GNU LGPL license. Some parts of the code are under the BSD 3-clause License. 


The main features of 7-Zip

  • High compression ratio in 7z format with LZMA and LZMA2 compression
  • Supported formats:
    • Packing / unpacking: 7z, XZ, BZIP2, GZIP, TAR, ZIP and WIM
    • Unpacking only: AR, ARJ, CAB, CHM, CPIO, CramFS, DMG, EXT, FAT, GPT, HFS, IHEX, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, QCOW2, RAR, RPM, SquashFS, UDF, UEFI, VDI, VHD, VMDK, WIM, XAR and Z.
  • For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip
  • Strong AES-256 encryption in 7z and ZIP formats
  • Self-extracting capability for 7z format
  • Integration with Windows Shell
  • Powerful File Manager
  • Powerful command line version
  • Plugin for FAR Manager
  • Localizations for 87 languages
7-Zip works in Windows 10 / 8 / 7 / Vista / XP / 2016 / 2012 / 2008 / 2003 / 2000 / NT.

Download 7-Zip and launch 7z457.exe to install the program

Next, browse to your file ending with the .001 extension

Right click the file and choose 7-Zip > Extract Here:



 The files should now be joined and have been extracted to the same directory that contains the .001-.009 parts.

If the program was originally an ISO, you may end up with a .bin file and a .cue file, you can then create a CD/DVD from the .bin file using your favorite CD/DVD creation software.