Software & Apps Windows Fix Cygwin1.dll Not Found or Missing 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 December 23, 2019 Cygwin1.dll error message. Tim Fisher / Lifewire Windows The Ultimate Laptop Buying Guide Tweet Share Email Cygwin1.dll errors are caused by situations that lead to the removal or corruption of the cygwin1 DLL file. In some cases, cygwin1.dll errors could indicate a registry problem, a virus or malware issue, or even a hardware failure. There are several different ways that cygwin1.dll errors can show up on your computer. Here are some of the more common ways that you might see cygwin1.dll errors: Cygwin1.dll Not FoundThis application failed to start because cygwin1.dll was not found. Re-installing the application may fix this problem.Cannot find [PATH]\cygwin1.dllThe file cygwin1.dll is missing.Cannot start [APPLICATION]. A required component is missing: cygwin1.dll. Please install [APPLICATION] again. Cygwin1.dll error messages might appear while using or installing certain programs, when Windows starts or shuts down, or maybe even during a Windows installation. The context of the cygwin1.dll error is an important piece of information that will be helpful while solving the problem. The cygwin1.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. How to Fix Cygwin1.dll Errors Do not download cygwin1.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 cygwin1.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 cygwin1.dll error. Install Cygwin, the source of the cygwin1.dll file. Try your best to complete this step. Installing or reinstalling Cygwin, the program that provides the cygwin1.dll file is a very likely solution to this DLL error. Restore cygwin1.dll from the Recycle Bin. Other than installing Cygwin, the easiest possible cause of a "missing" cygwin1.dll file is that you've mistakenly deleted it. If you suspect that you've accidentally deleted cygwin1.dll but you've already emptied the Recycle Bin, you may be able to recover cygwin1.dll with a free file recovery program. Recovering a deleted copy of cygwin1.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. Add the path of the cygwin1.dll file as a system environment variable. It's possible that a program that needs the cygwin1.dll file is looking for it through an environment variable that is missing or incorrect. You can fix this by adding the path of the DLL file (e.g. "C:\cygwin64\") as an environment variable. See this Stackoverflow thread if you need help doing this. This solution is only useful if you're not actually missing the cygwin1.dll file. Run a virus/malware scan of your entire system. Some cygwin1.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 cygwin1.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 cygwin1.dll error was caused by a change made to an important file or configuration, a System Restore could solve the problem. Update the drivers for hardware devices that might be related to cygwin1.dll. If, for example, you're receiving a "The file cygwin1.dll is missing" error when you play a 3D video game, try updating the drivers for your video card. The cygwin1.dll file may or may not be related to video cards - this was just an example. The key here is to pay very close attention to the context of the error and troubleshoot accordingly. Roll back a driver to a previously installed version if cygwin1.dll errors began after updating a particular hardware device's driver. Test your memory and then test your hard drive. We've left the majority of hardware troubleshooting to the last step, but your computer's memory and hard drive are easy to test and are the most likely components that might cause cygwin1.dll errors as they fail. If the hardware fails any of your tests, replace the memory or replace the hard drive as soon as possible. Repair your installation of Windows. If the individual cygwin1.dll file troubleshooting advice above is unsuccessful, performing a startup repair or repair installation might help. Use a free registry cleaner to repair cygwin1.dll related issues in the registry. A free registry cleaner program may be able to help by removing invalid cygwin1.dll registry entries that might be causing the DLL error. We rarely recommend the use of registry cleaners. We've included the 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 cygwin1.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 cygwin1.dll error using a troubleshooting step prior to this one. Troubleshoot for a hardware problem if any cygwin1.dll errors persist. After a clean install of Windows, your DLL problem can only be hardware related.