Windows operating system consists of many DLL files that are responsible for the proper functioning of the computer and its applications. Every DLL file is associated with some applications. But due to the corruption or missing of those files, you may get some error issues in the computer. Likewise you will see Zlib1.dll is missing error in Windows due to the missing or corrupt Zlib1.dll file. It is really a very annoying situation that should be resolved as soon as possible to avoid any data loss issue. You can use some manual or automatic methods given in this article to fix Zlib1.dll error. For automatic removal, you can use Advanced System Repair tool in the computer.