This latest version of ePSXe has not been updated in a while, though the latest update did improve a number of features including support for many games which tended to crash and the MDEC coder has been redone.
This program, though, will give you the opportunity to play your old PSX games directly on your Windows desktop. You can obtain the PSX Bios by using an action replay or by utilizing a gameshark. Though in order to be able to play these games you will require the PSX Bios which is only available if you are legally entitled to it.
EPSXe is a PS1 console emulator able to play discs issued for the original PlayStation system on your Windows Desktop.