regsvr32 “C:\Windows\System32\yourfile.dll” Step 2: Now all you have to do to register a DLL file is to type in the regsvr32 command, followed by the path of the DLL file. Step 1: First click on Start, then Run(Open command promot) If you need to register a DLL due to some sort of corruption or installation failure, you can do it manually by following the method outlined below. How can I do this in Windows 10? cd c:\windows\system32 Actually there is an existing DLL file and I'm trying to replace it. Hello, I am tried adding a DLL file in Windows 10 by copying to system32 folder, but I couldn't as Access Was Denied.