Error : Unable to copy file XYZ.dll. The process cannot access the file XYZ.dll because it is being used by another process

Resolution :

Go to windows command prompt  ( Click on Start -> Run -> Type cmd -> Press OK )

Type tasklist /m and Press enter

The above command will list all the process i.e exe and dlls each process is using

Find out which process i.e exe is using the dll XYZ.dll

Then go to Task Manager and End the process