001 File - opening and understanding

Did your computer fail to open a 001 file? We explain what they are used for and recommend software that we know can open or otherwise handle your .001 files.

What is a 001 file?

A .001 file is a 7-Zip split archive file. A file with the 001 file extension is often the first file in a set of multi-volume archive files created by 7-Zip. These files are similar to ZIP files; they contain multiple files that have been compressed (reduced in size) to save storage space and bandwidth.

When you create an archive file, 7-Zip lets you set a "volume size", which lets you split the output file into several files of the same size. This is useful if you know the output file will be huge, and you want to store it on e.g., CD, DVD, or floppy disks for backup purposes.

Each file is given a number as file extension, starting with 001 for the first file. All part files are needed to extract the content of the file archive. Start by opening the file with file extension 001, and your archiving tool will automatically prompt for the next volume as it decompresses the archive.

How to open 001 files

You will need a program compatible with the specific file you are trying to open, as different programs may use files with file extension 001 for different purposes. We have identified 3 001 openers for Windows that is compatible with this specific type of 001 file.

Programs that open these files

BitZipperBitZipperVerified
WinRARWinRARVerified
7-Zip7-ZipVerified
We have not yet verified any programs for Mac that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!
We have not yet verified any web services that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

Other file formats using extension .001

While 7-Zip split archive file is a popular type of 001-file, we know of 4 different uses of the .001 extension.

The 001 file extension indicates to your device which app can open the file. However, different apps may use the same file extension for different types of data. So a 001 opener may not be able to open all kinds of 001 files. In this case, look through all formats to make sure you find the best suited 001 viewer.

Central Point Backup data

Another use of file extension 001 is for backup files created by the old CP Backup software by Central Point Software.

This software is long obsolete and was acquired by Symantec in 1994.

While we have not verified the apps ourselves yet, our users have suggested 10 different 001 openers which you will find listed below.

Norton Backup file

Another program that used the 001 file extension was the old Norton Backup software for MS-DOS. It used 001 for the first data disk, 002 for the next, etc.

We're unsure if any of Norton's current offerings can restore these files, but we doubt it.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

DoubleSpace compressed disk volume

DoubleSpace was a compression technology used in MS-DOS and Windows 95, 98, and ME, which allowed the user to compress all data on a hard drive. At the time, hard drive size was limited and expensive, and this software solution that could help stuff more data onto hard drives by compressing it on-the-fly was popular.

The hard drive content was stored in a file with file extension 001. The DoubleSpace device driver was loaded at boot time and ensured all hard disk interaction by the operating system was intercepted and directed to this single compressed file.

You are only likely to come across this type of 001 files if you work with legacy hardware and old systems preservation.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

Various viewers for this file format

These apps are known to open certain types of 001 files. Remember, different programs may use 001 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Final Media PlayerFinal Media PlayerUser submitted
Switch Sound File ConverterSwitch Sound File ConverterUser submitted
PowerISOPowerISOUser submitted
Free File ViewerFree File ViewerUser submitted
ExpressZipExpressZipUser submitted
WavePad Sound EditorWavePad Sound EditorUser submitted
Pixillion Image ConverterPixillion Image ConverterUser submitted
DoxillionDoxillionUser submitted
BandizipBandizipUser submitted
PeaZipPeaZipUser submitted
We have not verified any software that we know for certain will work with 001-files on Mac. If you know one, please use the 'Suggest a program' link below and tell us about it!
We have not verified any web services that we know for certain will work with 001-files. If you know one, please use the 'Suggest a program' link below and tell us about it!