The BEST File Manager for Windows

Works with and greatly enhances:

Windows 11, 10

Windows 8, 7, Vista, XP

Servers 2003 and later

Starting at just $50 for home use and $69 for a business license (and a business two-pack for just $99!)

What's New / What's Up

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Version 4: the future

Major new tools, significant upgrades to current components and faster folder listings.

  • Find and rename problem files: bad paths, illegal characters, Linux & iOS (Mac) characters.
  • Check files and folders for compliance with different file systems e.g., NTFS, Fat-16, Fat-32, eFat, CDs, iOS, Linux and custom.
    Know if the files are right before you copy.
  • Delete files no matter their length or how they are named.
  • Powerful renaming with RegEx e.g. change 'Romeo Smith' into 'Smith, Romeo' and much more.
  • Lightening fast directory listing no matter how large the folder.
  • Detailed reports for copy errors.
  • Variable text size for views and dialogs.
  • and many more improvements and fixes..


See the V4 preview here.

Update May 2017

A May 2017 Microsft security update for Windows 10 conflicted with a major routine in FileBoss resulting in FileBoss not starting on some Windows 10 systems.

Versions V3.101 and later, fix the problem. You can read more about this at the page
Windows Creators Conflict.


Change File Extensions

Whether you want to add sequential numbers, change case, change filename extensions, remove or convert spaces, add folder names or each file's time to its name FileBoss has a quick and easy routine for doing so. And whether you are renaming files just a few at a time or batch rename by the thousands the routines work exactly the same.

How to change filename extensions

1) Select the files to have their extensions changed

In the following example we have the acts of Hamlet that all have the uppercase extension HTML. We will change all of the extensions to simple, lower-case htm for uniformity.

Naturally we could have also just selected a folder and told FileBoss to rename all the files in the folder.


2) Select Actions > Rename... from the main menu

Rename menu item on the Actions menu

3) Select the Change Filename Extensions tab

The display below shows all the tab. It is important to remember that when the OK button is pressed only the settings in the current tab - in this case the Transform tab - will be used to rename the files.

Click image for full-size view

  1. Click on the Change Extensions tab it is not already selected.
  2. Select the Change to: radio button and enter htm in the box to the right.

4) Confirm the renamed files

After pressing the OK button in the above step, FileBoss will find the first file to be renamed and display a confirmation dialog similar to the one below with the new filename extension displayed in its own field on the right

You can continue to rename or skip each file individually or at any time you can Rename All the rest of the files or Skip Rest thus ending the renaming.

Note that you can edit the new name anyway you like and then press the Rename button giving you total control over how the file is named.

5) See the results

When FileBoss has finished changing the filename extensions the new names will appear immediately in the Contents window with all their extensions set to lower case htm.