Software & Apps Windows How to Fix Unidrv.dll Not Found or Missing Errors A troubleshooting guide for unidrv.dll errors by Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated on April 14, 2020 Windows The Ultimate Laptop Buying Guide Tweet Share Email Unidrv.dll errors are caused by situations that lead to the removal or corruption of the unidrv DLL file. In some cases, unidrv.dll errors could indicate a registry problem, a virus or malware issue, or even a hardware failure. The unidrv.dll error message could apply to any program or system that might utilize the file on any of Microsoft's operating systems, including Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, and Windows 2000. Unidrv.dll Errors There are several different ways that unidrv.dll errors can show up on your computer. Here are some of the more common ways that you might see unidrv.dll errors. Unidrv.dll Not FoundThis application failed to start because unidrv.dll was not found. Re-installing the application may fix this problemCannot find [PATH]\unidrv.dllThe file unidrv.dll is missingCannot start [APPLICATION]. A required component is missing: unidrv.dll. Please install [APPLICATION] again The unidrv.dll file is associated with Microsoft's Universal Printer Driver. It's normally stored in a folder like C:\WINDOWS\system32\spool\drivers\w32x86\ or within a subfolder of C:\Windows\System32\DriverStore\FileRepository\. The context of the unidrv.dll error is an important piece of information that will be helpful while solving the problem. Unidrv.dll error messages might appear while using or installing certain programs, when Windows starts or shuts down, or maybe even during a Windows installation. How to Fix Unidrv.dll Errors Do not download unidrv.dll from a "DLL download" website. There are many reasons why downloading a DLL file is a bad idea. If you need a copy of unidrv.dll, it's best to obtain it from its original, legitimate source. Start Windows in Safe Mode to complete any of the following steps if you're unable to access Windows normally due to the unidrv.dll error. Restore unidrv.dll from the Recycle Bin. The easiest possible cause of a "missing" unidrv.dll file is that you've mistakenly deleted it. If you suspect that you've accidentally deleted unidrv.dll but you've already emptied the Recycle Bin, you may be able to recover unidrv.dll with a free file recovery program. Recovering a deleted copy of unidrv.dll with a file recovery program is a smart idea only if you're confident you've deleted the file yourself and that it was working properly before you did that. Run a virus/malware scan of your entire system. Some unidrv.dll errors could be related to a virus or other malware infection on your computer that has damaged the DLL file. It's even possible that the unidrv.dll error you're seeing is related to a hostile program that's masquerading as the file. Use System Restore to undo recent system changes. If you suspect that the unidrv.dll error was caused by a change made to an important file or configuration, a System Restore could solve the problem. Run the sfc/scannow System File Checker command to replace a missing or corrupt copy of the unidrv.dll file. Since this DLL file is provided by Microsoft, the System File Checker tool should restore it. Install any available Windows updates. Many service packs and other patches replace or update some of the hundreds of Microsoft distributed DLL files on your computer. The unidrv.dll file could be included in one of those updates. Update the printer drivers. Since the unidrv.dll file is associated with Microsoft's printer driver, updating it should fix any "unidrv.dll is missing" or related errors. Probably the easiest way to update this print driver is to install any missing Windows updates (Step 5), but using a driver updater tool could be useful, too. Reinstall the printer driver using these instructions if you're using Windows 3.1. Extract unidrv.dll from its original source, the CAB file. There's a CAB file in Windows XP where the unidrv.dll file is copied from when Windows is first installed. Open this file and you'll be able to pull the unidrv.dll file from it and put it wherever the error message says the file is missing from. To do this, open the C:\Windows\Driver Cache\i386\ folder and look for a service pack CAB file, like sp3.cab if Windows XP is updated to service pack 3. Open the CAB file with a file unzip tool like 7-Zip and then copy the unidrv.dll file out of it. It seems that unidrv.dll error messages are more common on Windows XP, but if you're seeing one in a newer version of Windows, use Everything to search for a copy of unidrv.dll elsewhere on the computer that you can copy to where it needs to be. Reinstall the program that uses the unidrv.dll file. If the unidrv.dll DLL error occurs when you use a particular program, reinstalling the program should replace the file. Roll back a driver to a previously installed version if unidrv.dll errors began after updating a particular hardware device's driver. Repair your installation of Windows. If the individual unidrv.dll file troubleshooting advice above is unsuccessful, performing a startup repair or repair installation should restore all Windows DLL files to their working versions. Use a free registry cleaner to repair unidrv.dll related issues in the registry. A free registry cleaner program may be able to help by removing invalid unidrv.dll registry entries that might be causing the DLL error. We rarely recommend the use of registry cleaners. They're included as an option here as a "last resort" attempt before the destructive step coming up next. Perform a clean installation of Windows. A clean install of Windows will erase everything from the hard drive and install a fresh copy of Windows. If none of the steps above correct the unidrv.dll error, this should be your next course of action. All the information on your hard drive will be erased during a clean install. Make sure you've made the best attempt possible to fix the unidrv.dll error using a troubleshooting step prior to this one. Troubleshoot for a hardware problem if any unidrv.dll errors persist. After a clean install of Windows, your DLL problem can only be hardware related. Need More Help? If you're not interested in fixing this problem yourself, see How Do I Get My Computer Fixed? for a full list of your support options, plus help with everything along the way like figuring out repair costs, getting your files off, choosing a repair service, and a whole lot more.