Xorgconfig is not a Zenwalk specific tool, just part of the xorg package.
Make a backup of your current xorg.conf (/etc/X11/xorg.conf). First collect the data of your computer hardware. Check your monitor documentation for refresh rates and possible resolutions. Check which video card you are using - brand, model, amount of onboard RAM. Check the protocol your mouse uses, if it has a scroll wheel, and how many buttons it has. Take into account that a scroll wheel counts as three buttons (click - forward scroll - backward scroll). Check the keyboard type you use (azerty or qwerty) and how many keys it has (probably an international 105-key one). Now that you have the right info, launch xorgconfig from text mode, as root. Xorgconfig is an interactive program - it will ask you questions. If you have gathered the information provided above, it will be a piece of cake to answer them. Once you have completed xorgconfig's procedure, save it. Then reboot into graphical mode and behold the fruit of your work.