Here are some troubleshooting techniques to reduce the probability of encountering Illegal Operation Errors in Windows 95

This information was provided by Claris Corporation on 16 March 1998, and incorporated into Apple Computer's Tech Info Library.

In Windows 95, it is never completely clear why Illegal Operation Errors occur. The reasons for these errors can be anything from the printer driver to the type of hard drive controller. It is best to make sure that you are using the latest video driver and printer driver for your system before you move on to the following troubleshooting steps.

Here are some things to try:

1] Use the ctrl-alt-del function to bring up the task list. There is a possibility that a program that you have running in the background might be conflicting with the application that reported the illegal operation error. The only programs that you need to run in the background are a] explorer and b] systray. You should use the end task function to make sure that your application has the full attention of your CPU.

2] Run scandisk.exe and defrag.exe on your hard drive(s). These are basic programs that come installed on Windows 95 machines and they searche for general maintenance errors and fix them.

3] a) In the Start menu, select control panels and system. In system, select performance and then file system. The typical role of the machine should be set to network server.

b) Chances are the illegal operation error occurred because of a memory conflict in your system. This may result because there wasn't enough memory available for the specific application being used. Everything about Windows 95 is memory related. If you installed Windows 95 using the default configurations, your machine is using virtual memory. You can check this by going to settings from the start menu/control panels/ system/performance/virtual memory. Select "let me manage my own virtual memory settings". The virtual memory settings should be: the minimum swap file size should be the amount of memory that you have installed and the maximum swap file size should be set to your memory installed doubled. For example, on a machine that has 16mb ram installed, your minimum swap file size should be set to 16mb and your maximum swap file size should be set to 32mb.

The best defense against the Illegal Operation Error message in Windows 95 is maintenance. If you can make sure that all of the above steps have been performed, you can reduce the probability of getting the dreaded Illegal Operation Error message in Windows 95.