System error 85 has occured

The System error 85 has occurred or in full the System error 85 has occurred. The local device name is already in use. is one of Microsoft's error messages that is related to mapping network drives.  It is one of the error messages that can make your hair grow gray.

The System error 85 has occurred error message is also similar to the System error 67 has occured message. As these two messages demonstrate, Microsoft Windows is in some cases very good in hiding the relevant information from the user, despite attempting to be user-friendly.

This error message happens most commonly when trying to map a network drive. In a nutshell, this message happens because the network drive letter you are trying to use for another mapping had already been used by some other resource.

The System error 85 has occured is most annoying when trying to map a network drive using the NET USE command.

System error 85 has occurred related to Terminal Services

Terminal Services is a component of Microsoft Windows that allows a user to access applications and data on a remote computer. In many cases, when you work on a computer in an enterprise setting, your computer often accesses data shared on other servers, network shared folders, or even workstations.

For this to happen, your computer needs to run the Terminal Services service. You can find it running in your Services.

Now, let's explain where the System error 85 has occurred comes into play. When you try to connect a drive using drive letter that was previously connected to a Distributed File System (DFS) resource, in layman's terms that means to a folder shared on a network, you may receive the following error message:

System error 85 has occurred. The local device name is already in use.

This error message usually persists for a particular drive letter in that particular Terminal Services session. When a particular Terminal Services session uses a drive letter already associated with some other resource, you cannot use it to map another resource. That is clear and easy. The problem is that Windows is good in hiding resource utilization of your drive letters. In other words, even though you think that you do not use for example drive letter M for anything, the contrary can be the truth.

How to fix the System error 85 has occurred?

One thing to mention is that even though you may be mapping some drive letter to a network resource, the same drive letter for other Terminal Services sessions may work as expected.

Use another drive letter...

Another point is that a different drive letter that is not typically used also works as expected. If it is feasible for you, use different drive letter when mapping to your network resource.

Restart Terminal Services-based component...

If using another drive letter to map your network resource is not an option, you can try to correct the issue by restarting the Terminal Services-based component.

Restart Terminal Services...

Another way to fix the problem is to restart the whole Terminal Services service. You can do so by executing the following steps:

-> Go to the Start Menu
-> Run
-> Type services.msc and hit ENTER
-> Locate Terminal Services
-> Right click it and select RESTART

Upgrade Windows...

The good news is that some attempts have been made by Microsoft to handle this error message and the underlying causes by Windows. The System error 85 has occurred was often visible in Microsoft Windows 2000. The Service Pack 3 and Service Pack 4 include some fix for this.

What to consider when mapping a network drive

Mappings that are made under the SYSTEM account are global. If you have some service that might be creating mappings using SYSTEM credentials, those are not local to the login session as they are for normal users.

System error 85 occurred related message

The System error 85 occurred message is very similar to the System error 67 has occurred as it also relates to mapping. The System error 67 occurred error message is triggered when the network resource cannot be located.

I need help with System error 85 has occured

See our discussion forum, you can find some answers in regards to the System error 85 has occured message there.

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