How does older software work on Windows 7?

Windows 7 is the latest Windows operating system with great graphics and productivity features. Windows 7 ultimate version has a special XP mode which allows you to use enterprise software which were made for Windows XP operating system and were not updated to Windows 7. Microsoft did this to increase the adaptation rate of Windows 7 operating system in enterprise environment. Other than the special XP Mode, Windows also provides compatibility mode. In the compatibility mode you can make older programs run in Window Vista, Windows Vista Service Pack 1, Vista Service Pack 2, Windows Server 2003, Windows XP Service pack 2 and 3, Windows 2000, Windows NT 4.0 service pack 5, Windows 98, Windows ME, and Windows 95. The compatibility mode is not perfect but it does work most of the time. To turn on compatibility for programs, take the following steps – click on the Start button and select Control Panel. In the search box, type troubleshooter, and then click Troubleshooting. Under Programs, click Run programs made for previous versions of Windows.

You want to run Lotus123 version 5 which was introduced in the Windows 3.1/95 era. Which means it is a really old program and is not even supported by the creator. Using such a program is inadvisable as they could be exploited and you are missing on lots of new features and improvements of latest programs. Try out the latest version of excel or just update your Lotus software.