File Extension/123
alphabetical list of extensions

File extension .123

Description of the problem
If you have on your computer a .123 file that you cannot open, you are in exactly the same situation as thousands of other people who have similar problems with this or any other unknown file.

There may be several reasons why you cannot open the file with .123 extension. Directly on this website you can find a solution of the most common problem with the .123 file – that you do not have on your computer the appropriate program to open the file.
Solution
From the list below, select the appropriate program, install it and double click on the icon of a file that did not want to open - the problem with the .123 file extension should be solved. However, if this does not happen, go back to the website to learn about other possible causes of the error, which have been described at the bottom of the website.
Category
Spreadsheet Files
Developer
IBM
Popularity
StarStarStar
File name: Lotus 1-2-3 Spreadsheet
Programs that will open this file:
Windows
Windows
Apache OpenOffice Apache OpenOffice
Corel Quattro Pro Corel Quattro Pro
Gnumeric Gnumeric
Lotus 1-2-3 Lotus 1-2-3
WordPerfect Offic WordPerfect Offic
Mac OS
Mac OS
Apache OpenOffice Apache OpenOffice
NeoOffice NeoOffice
Linux
Linux
Apache OpenOffice Apache OpenOffice
Gnumeric Gnumeric
Category
CAD Files
Developer
Sunstone Circuits
Popularity
StarStarStar
File name: PCB123 Circuit Board Design
Programs that will open this file:
Windows
Windows
PCB123 PCB123
Remember!
The .123 file extension can correspond to several not related file formats. If there is more than one file format with the .123 extension, you will probably find most of them at this website. Remember that you need to download a program to support a particular file type. So first look through the entire contents of the website to select a program to support just the file you have.

Other possible reasons why your .123 file does not want to open

In addition to the problem described above, i.e. the lack of the appropriate application to support the .123 file, there may be several reasons that cause problems with opening and operation of the data format:

1. Incorrect version of the installed application

A quite common problem is the lack of application in the appropriate version. Even if you have an application, with the help of which you should open the .123 file, you may have a problem with it because of its version. Perhaps in previous versions the application has not yet supported the .123 file, so download the update and check again.

2. Incorrect .123 file association with the program

If you have already installed the appropriate application, and it is the correct version, the file may not open correctly, because the operating system does not have information that this program supports the file. So you need to "show" which program the computer should use. To do this:

  • Right-click the .123 file
  • Go to the "Open with" - then "Choose default program ..."
  • Locate the appropriate application
  • Click "OK"

3. The file is corrupt

It also happens that the file you want to open is corrupt and therefore there is no such possibility. In this situation, you should find its different version, or ask a person from whom you got, to send it again.