> ## Content Index > Fetch the complete content index at: https://nolongerset.com/llms.txt > Use this file to discover other available public pages before exploring further. # UNC Alias for a Local Folder - URL: https://nolongerset.com/unc-alias-for-a-local-folder/ - Published: 2021-11-13T21:22:31.000Z - Updated: 2026-05-08T13:00:08.000Z - Description: The subst command lets us mimic mapped network drives. But what if your backend tables are linked using UNC paths? Don't worry. We can handle those, too! - Author: Mike Wolfe - Tags: Professional Development, Testing, Advanced, #Import 2026-05-20 02:59 You should never develop using production data. ## The Simple Case: Drive Letter Mapping Most of our clients that use file-based back-end databases use drive letters to map to the network drives where those files are stored, such as `P:\Data\MyDb.accdb`. With that approach, it is easy for us to host development copies of the database files on our local machines, for example `D:\MyClient\Data\MyDb.accdb`. Then, when working on that application, we can use the `subst` command to mimic the client's environment while pointing to our development data: ```batch subst P: D:\MyClient ``` ## The Trickier Case: UNC Paths One of our clients prefers to use UNC paths to connect to back-end Access databases on their network. Those are the paths that start with double backslashes, such as `\\MyServer\MyShare\Data\MyDb.accdb`. Creating local aliases that mimic UNC paths on your local computer is much trickier. ### Modifying the Local Hosts File: A Failed Approach My first attempt was to edit my local hosts file and point "MyServer" at the loopback IP address, 127.0.0.1\. I thought that I could then share a folder from my local device and connect to it using the standard `net use` command. Alas, this did not work. I was never able to get past the authentication step. No matter what accounts I tried, it always said I had entered a bad user name or password. I do think editing the hosts file might have worked if the development data was on a *different* Windows machine. ### Modifying the Registry: A Viable Approach After exhausting all the user name-password combinations I could think of, I abandoned the idea of using the local hosts file. Instead, I asked the internet for help. The internet delivered. In an article titled, *[Creating a NetBIOS alias for the local machine](https://blog.malevy.net/2010/05/creating-netbios-alias-for-local.html),* Michael Levy provided the keys to the UNC alias kingdom. To make it work, you have to create four new registry entries. The first two entries are needed to allow the feature to work: > **HKEY\_LOCAL\_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\lanmanserver\\parameters** > > Add a new DWORD value called **DisableStrictNameChecking*.* > Set its value to **1**. > > > **HKEY\_LOCAL\_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\lanmanserver\\parameters** > > Add a new DWORD value called **DisableLoopBackCheck** > Set its value to **1**. The next two entries contain the actual aliases for your machine name. Continuing with the examples from above, we would add one value to each of these Multi-String Values: `MyServer`. > **HKEY\_LOCAL\_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\lanmanserver\\parameters** > > Add a new Multi-String value called **OptionalNames**. > Enter one or more aliases, one per line. > > > **HKEY\_LOCAL\_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\Lsa\\MSV1\_0** > > Add a new Multi-String Value **BackConnectionHostNames**. > Enter one or more aliases, one per line. #### Forcing the registry changes to take effect To enable the changes, you'll need to **restart the *Server* service**. From an **admin command prompt**, execute the following commands: ``` net stop server net start server ``` If that does not work for whatever reason, try a full system restart. #### Share your local drives To finish the process, you will need to create a share on your local computer with the same name as the client's share. **NOTE**: The Share Name *does not* need to be the same as the Folder Name. For example, I can share the `\MyClient\` folder on my computer as `\MyShare\` so that it matches the client's environment: - Right click on the `\MyClient\` folder - Choose *Properties* - Go to the *Sharing* tab - Click on \[Advanced Sharing\] - Check the box to *\[√\] Share this folder* - Set the Share name to `MyShare` - Click \[OK\] ![](https://storage.ghost.io/c/eb/d7/ebd732c1-5f03-4f07-b386-5d08557e15c9/content/images/2021/11/image-42.png) #### Test it out - Open File Explorer - Navigate to `\\MyServer\MyShare` You should see the contents of your `D:\MyClient\` folder. You can now put your development data files in this folder. This allows you to see them from your front-end Access file without having to relink the tables when moving between development and production. ## BUG ALERT *\[Updated 2022-01-18\]* Microsoft broke this feature with a recent security update. Read my [bug alert article](https://nolongerset.com/bug-alert-unc-alias/) for details: [Bug Alert: Can’t Access Shared Folders via UNC AliasUNC aliases are a great way to set up development environments for Access applications that rely on UNC paths. It’s too bad Microsoft broke them.![](https://nolongerset.com/favicon.png)No Longer SetMike Wolfe![](https://storage.ghost.io/c/eb/d7/ebd732c1-5f03-4f07-b386-5d08557e15c9/content/images/2022/01/UNC-Alias-Bug-Alert.jpg)](https://nolongerset.com/bug-alert-unc-alias/) --- ### External articles [Creating a NetBIOS alias for the local machineMy current assignment is with a client that has a system consisting of multiple components where each component is a separate .EXE. This wou...![](https://blog.malevy.net/favicon.ico)Mostly Ramblings...Michael Levy![](https://resources.blogblog.com/img/icon18_edit_allbkg.gif)](https://blog.malevy.net/2010/05/creating-netbios-alias-for-local.html)