In the modern world of global businesses & technology, accounting and bookkeeping solution has become a primary necessity. Therefore, for the benefit & rapid growth of companies with no hassle, Intuit Inc. developed an accounting software that is – QuickBooks. This software has garnered an immense reputation in the business market of the United States & Canada. In this article, We will discuss QuickBooks Error Code 3100.
But in the last few years, it has been observed by a few users that this is frequently get affected by the QuickBooks Error Code 3100. Here in this post, we are going to endow the best information from our understanding of this issue. We will provide a complete overview of the symptoms, causes, and solution of the QuickBooks error code 3100. However, you can take guidance from our QuickBooks error support services in case you have any queries or looking for help.
Read Also: How to Fix QuickBooks Error Code 6007?
What is QuickBooks Error Code 3100?
QuickBooks Error Code 3100 generally occurs when you try to add a new customer to QuickBooks. The Customer, Vendor, or Employee name or record you are trying to enter may already exist in the create Customer request. The accounting software always takes unique Full Names in Customer, Vendor, or Employee data and that includes both active and inactive records. You should check the names for the three entity types if this error appears and then rename that if necessary.
When this error occurs you will see the following error message on your screen:
Customer Insert/Update Error – [CustomerName] – 3100 – The name “[CustomerName]” of the list element is already in use.
QuickBooks Error 3100 Symptoms
Check out the signs and symptoms of QuickBooks error code 3100 given below:
- Frequent active program window crashes
- QuickBooks Error Code 3100 pop-up on the screen
- System crashes after regular intervals of time
- Keyboard inputs & mouse responds slowly
- Generally, Error 3100 appears when QuickBooks installation
What Causes QuickBooks error code 3100?
Check out the reasons why QuickBooks Error code 3100 occurs:
- Corrupt QuickBooks download or incomplete QuickBooks installation
- Corrupt or damaged Windows registry
- Attack of harmful viruses & malware
- Mistakenly deleted QB programs/files
The image as shown below is similar which appears on your desktop

Read this also: What versions of QuickBooks are supported on Windows 10?
How to Troubleshoot QuickBooks Error Code 3100?
Check out the systematic troubleshooting steps to resolve QuickBooks Error Code 3100:
Step 1: Use Unique Customer, Vendor, or Employee Names
- Use appropriate credentials and login into your Salesforce account.
- Click on the Accounts tab.
- Select Merge Accounts at the bottom right side of the window.
- Type in the name of the duplicate account in the text field and proceed to validate for merging them. Remember to not remove the Customer List ID value.
- You should now be able to add a new customer, vendor, or employee.
If the issue persists, perform the below-mentions solutions.
Step 2: Repair Windows Registries Associated with Error 3100
Steps to repair the Windows registries are given below:
- Firstly, Hit the “Start” or “Windows” tab.
- After that Enter the “command” in the dialogue box… DO NOT hit ENTER yet.!
- Now Press Ctrl+Shift on the keyboard and press the ENTER tab.
- You will be redirected to the permission dialogue box.
- Hit the “Yes” icon.
- The “command prompt” will open with a blinking cursor.
- Type the “regedit” & press the ENTER.

- Choose the keys related to the error 3100 in the “Registry Editor”.
- In the File menu, select the Export.

- Choose the folder that you want to save in your Save In list.
- Enter the name of QB backup files for which you want to create the backup in “File Name” box.
- Ensure that the “Selected branch” chosen in the Export Range box.
- Hit the Save icon.
- Finally, the file will save with a .reg extension.
Step 3: Conduct the Full System Malware Scan

- Run the full system scan on your anti-virus software to remove the entire malicious viruses.
Also See: Steps to enter and delete transactions by batch in QuickBooks desktop
Step 4: Cleanup the System Junk
As we use our system daily, the system accumulates dozens of junk files & programs. It may slow down your system or cause the error code 3100..! Hence, use the antivirus software to eliminate the gibberish files, folders, and programs out from the computer. Use the below given steps to remove junk files through Disk Cleanup (cleanmgr).
- Hit the “Start” or “Windows” button.
- Enter the “command” in the search box… DO NOT hit the Enter yet..!
- Press the Ctrl+Shift & hit the Enter tab.
- You will be redirected to a permission dialog box.
- Click the “Yes” icon.
- The command prompt will appear.
- Type the “cleanmgr” & hit the Enter tab.

- Disk Cleanup will estimate the occupied disk space.
- Check the boxes & hit the OK icon.
Step 5: Update the System Drivers

- Go to Programs and Features.
- Find NETGEAR Adapter and right click to select Uninstall.
- Restart you computer and reinstall the software drivers again using the CD or the website.
- When prompted, plug in or insert the adopter in order to keep from countering any conflicts with existing devices.
See Also: How to Create one-time Payroll Check in QuickBooks Online?
Step 6: “Undo” the Recent System Changes by Using Windows System Restore
- Hit the “Start” or “Windows” button.
- Type “System Restore” in the search box & hit the “Enter”.
- Hit the System Restore.

- If prompted, enter the administrator password.
- Finally, restore the system.
Step 7: Uninstall & Reinstall the QuickBooks Program (Windows 7, Windows Vista, XP, 8)
- First of all you need to Hit the “Start” button to open the Programs and Features.
- After that, Click the “Control Panel”.
- Click the “Programs”.
- Click the “Programs and Features”.

- Trace the QB programs associated with the “QuickBooks Error Code 3100″.
- Select the QuickBooks associated entry.
- Hit the Uninstall button.

- Finally, reinstall the QuickBooks software.
Also See: How to Fix QuickBooks error code 1303?
Final Words..!
It might be possible that the above manual steps might not help out in order to troubleshoot the QuickBooks error code 3100. Or possibly you couldn’t perform the above steps accurately..! Well, you can contact Intuit-certified professionals immediately for support. Our experts will get in touch with you shortly.
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