Error for every emulator i download?

Hi guys I used to use ePSXe as an emulator when I accidentally deleted a file I thought was part of another program it stopped working. I have tried to reinstall it numerous times but everytime I unzip it now and try to open the program a system error comes up saying the program couldn't run because zlib1.dll is missing from my computer and totry re-installing it. I've tried using other emulators and they all give me some type of error like that. I'm using a relatively new hp. If anyone could help me out it would be awesome I miss playing all the old psx games.

windows 7 premium 64bit
hp pavillion d7 notebook
4038mb ram
directx ver 11
AMD Phenom II N830 tri-core 2.1ghz

:google: the zlib.dll
Then put the dll file in the emu's folder

incase you cant find it here is a link

Thanks guys the link helped a ton, not exactly computer savvy do you know where to get the bios file to configure the ePSXe?

if you go to the main site http://emuparadise.org and click emulation extras on the left hand side bar and click bios images look for the PSX or PS1 bios images :)

thanks!