What to do when Userdata.dll is missing in Windows 10

Matthew Adams
by Matthew Adams
Windows & Software Expert
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Windows 10 Redstone 5 RTM build

Steps to solve userdata.dll problems

  1. Run a System File Checker Scan
  2. Scan the Registry With CCleaner
  3. Remove Programs From the Windows Startup
  4. Roll Back Windows With System Restore
  5. Update Device Drivers
  6. Reinstall the Software
  7. Get a New Userdata.dll File
  8. Add DLL Fixer Software to Windows

Userdata is a shared DLL (Dynamic Link Library) system file that some software need to run. Some users have stated that a userdata.dll error message pops up whenever they start Windows. A userdata.dll error message might also pop up when you try to manually open a specific program.

The userdata.dll error message states: This application failed to start because userdata.dll was not found. Reinstalling the application may fix this problem.


That error message usually pops up when the userdata.dll is either missing or corrupted in someway. Consequently, software that need the userdata file can’t access it. The same error message can pop up for other DLL files, and the fixes for it are pretty similar. This is how you can fix the userdata.dll is missing error message in Windows 10.

How to fix userdata.dll issues

Solution 1: Run a System File Checker Scan

As userdata is a DLL system file, the System File Checker might fix the missing userdata.dll error. System File Checker is a command-line utility that scans for system file corruption. SFC doesn’t always fix corrupted files, but it’s worth a shot nonetheless. You can initiate an SFC scan in the Command Prompt as follows.

  • Press the Type here to search button on the taskbar to open Cortana.
  • Enter ‘Command Prompt’ in the search box.
  • Right-click Command Prompt and select Run as administrator to open its window.

  • Next, enter ‘DISM.exe /Online /Cleanup-image /Restorehealth’ in the Prompt and press Return before you initiate the SFC scan.
  • Then input ‘sfc /scannow’ in the Prompt, and press the Enter key.

  • Restart Windows if Windows Resource Protection does repair corrupted files.

— RELATED: How to fix a corrupt bootres.dll file in Windows 10

Solution 2: Scan the Registry With CCleaner

The userdata.dll error message can also be due to invalid userdata registry entries. So scanning the registry with a reputable utility might fix the userdata.dll error message. The freeware CCleaner version is among the foremost registry cleaners. You can fix registry entries with CCleaner as follows.

  • Click the green Download button on this webpage to save CCleaner’s setup wizard to hard drive.
  • Open CCleaner’s installer to install the registry cleaner.
  • Click Registry on the left of CCleaner’s window to open the registry cleaner.

Clean registry errors

  • Select all the registry check boxes, and press the Scan for Issues button.
  • Click the Fix selected Issues button.
  • A dialog box will open where you can select to back up the registry. Although you probably won’t need it, select the Yes option if you prefer to save a backup file.

  • Press the Fix All Selected Issues button to repair the registry.

Solution 3: Remove Programs From the Windows Startup

Some Lenovo laptop users have said that the userdata.dll error message pops up when they start-up Windows. They fixed the issue by removing the Lenovo Password Manager Pro and Fingerprint Reader programs. Thus, it might be the case that a startup program generates the error message. So removing software from the system startup is another potential fix for the userdata.dll error. This is how you can disable startup software in Windows 10.

  • Open the Win + X menu with the Windows key + X hotkey.
  • Select Task Manager on the menu to open the window  in the snapshot directly below.

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  • Click the Start-up tab shown directly below.

  • Then you can remove programs from the Windows startup by selecting them and clicking Disable.
  • Alternatively, you can strip down the Windows startup by deselecting the Load startup items option in System Configuration. Press the Windows key + R hotkey, enter ‘msconfig’ in Run and click OK to open the window shown below.

typing lag/slow keyboard response in Windows 10

  • Then click the Selective startup radio button option on the General tab.
  • Deselect the Load startup items check box.
  • Click the Apply and OK buttons.
  • Click Restart on the System Configuration dialog box that opens.

— RELATED: Full Fix: Autorun.dll errors in Windows 10, 8.1, 7

Solution 4: Roll Back Windows With System Restore

System Restore can come in handy for fixing corrupted DLL files. With that utility, you can restore Windows 10 to an earlier point in time, which can fix corrupted system files. System Restore might fix the userdata.dll is missing error if you can select a restore point that will restore Windows to a date when the DLL error message did not pop up on your laptop or desktop. This is how you can roll back Windows.

  • To open System Restore, right-click the Start menu and select Run.
  • Enter ‘rstrui’ in Run’s Open text box and click OK to open System Restore’s window.

  • Click the Choose a different restore point option as an alternative to the recommended restore.
  • Press the Next button to open the list of restore points.

  • To view the full restore list, click the Show more restore points option.
  • Choose a restore point to roll Windows back to.
  • Restoring Windows removes programs installed after a selected restore point. You can press the Scan for affected programs button to see what software is deleted for a specific restore point.

  • Click Next and Finish to roll back Windows.

Solution 5: Update Device Drivers

Some users have stated that updating hardware drivers fixed the userdata.dll is missing error. So updating outdated or corrupted drivers is another potential resolution for the userdata.dll error. However, it’s hard to tell what drivers you’ll need to update. Your best bet is to add software to Windows 10 that will scan your drivers.

Driver Booster 6 is software that you can update AMD, Nvidia and Intel drivers with among others. You can add the freeware version to Windows platforms by clicking Free Download on this webpage. The software automatically scans drivers and lists any that need updating when you launch it. Select the Outdated check box, and click the Update Now button to update the drivers.

Driver Booster 5 pro

Solution 6: Reinstall the Software

If the userdata error message pops up for a specific program, reinstalling that software might fix the error. The userdata.dll is missing error message states, “Reinstalling the application may fix this problem.” So that’s one hint for fixing the DLL error. This is how you can reinstall the program.

  • Right-click the Start button to open the Win + X menu, and click Run on that menu.
  • Input ‘appwiz.cpl’ in Run and click OK to open the Control Panel applet shown directly below.

  • Select the program that returns the DLL error message, and click the Uninstall button.
  • Click the Yes button to confirm.
  • Restart Windows after uninstalling the program.
  • Then reinstall the latest version of the software. You can usually download the latest version from the software’s website.

— RELATED: Full Fix: Rundll32.exe error in Windows 10, 8.1, 7

Solution 7: Get a New Userdata.dll File

If the userdata.dll file has been deleted, you can get a new one from DLL-Files.com. DLL-Files.com is among the more reputable sources for DLL files. This is how you can get a new userdata file from that website.

  • Open this webpage in your browser.
  • Click Download to save the userdata.dll ZIP.

  • Open the userdata ZIP in File Explorer.
  • Press the Extract all button.

  • Click Browse to select a folder path to extract the ZIP to, and click the Extract button.
  • Open the extracted userdata.dll folder in File Explorer.
  • Select the userdata.dll file, and press the Copy to button.

  • Select to copy it to the System32 folder.
  • Then select the original userdata.dll file in the folder you exacted it to, and press the Delete button.
  • Restart your desktop or laptop.
  • You might also need to register the DLL file. To do so, press the Windows key + X hotkey and select Command Prompt (Admin).
  • Enter ‘regsvr32 userdata.dll’ in the Command Prompt’s window, and press the Return key.

  • Click Restart on the Start menu.

Solution 8: Add DLL Fixer Software to Windows

There are numerous DLL fixer software for Windows that fix DLL errors. DLL Suite, DLL Tool, DLL Files Fixer and Free DLL Fixer are some of the utilities that scan for and repair corrupted DLL files. They also include databases that you can get replacement DLL files from. As such, those utilities might come in handy for fixing the userdata.dll is missing error. DLL Suite is retailing at $9.99, and you can try out an unregistered version of that software by clicking the Start Download button on this page.

Those are a few resolutions that will probably fix the userdata.dll is missing error in Windows 10. Note that some of the above resolutions might also fix missing DLL error messages for other files.

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