There are many reasons whydownloading a DLL file is a bad idea.
Restore zlib.dll from the Recycle Bin.
The easiest possible cause of a “missing” zlib.dll file is that you’ve mistakenly deleted it.

Download zlib.zipand then extract zlib.dll file from it.
launch the program with administrative rights.
We’ve seen zlib.dll errors fixed this way for PC video games.
Run a virus/malware scan of your entire system.
Use System Restore to undo recent system changes.
Reinstall the program that uses the zlib.dll file.
Try your best to complete this step.
Update the drivers for hardware devicesthat might be related to zlib.dll.
The zlib.dll file may or may not be related to video cardsthis was just an example.
The key here is to pay very close attention to the context of the error and troubleshoot accordingly.
Install any available Windows updates.
Manyservice packsand other patches replace or update some of the hundreds of Microsoft distributed DLL files on your gear.
Test your memoryand thentest your hard drive.
If the hardware fails any of your tests, replace the memory orreplace the hard driveas soon as possible.
Repair your installation of Windows.
Use a free registry cleanerto repair zlib.dll related issues in the registry.
We rarely recommend the use of registry cleaners.
Perform a clean installation of Windows.
This erases everything from thehard driveand installs a fresh copy of Windows.
If none of the steps above correct the zlib.dll error, this should be your next course of action.
All the information on your hard drive will be erased during a clean install.
Troubleshoot for a hardware problemif any zlib.dll errors persist.
After a clean install of Windows, your DLL problem can only be hardware related.
Need More Help?
In some cases, zlib.dll errors could indicate aregistryproblem, a virus or malware issue, or even ahardwarefailure.
There are several ways zlib.dll errors can show up on your system.
Here are some of the more common error messages you might see: