There are a few reasons you might want to change your router, switch, or other network hardware password. An obvious reason to change your password is if you think your network has been compromised somehow.
In most cases, though, you'll change the password to your router or switch so you're no longer using the default password set by the factory. No device, especially a router, should ever be in operation with the default password because these passwords are published and freely available.
Luckily it's very easy to change the password to your router or other network device.
The exact steps involved in changing the password can differ from device to device and especially from manufacturer to manufacturer.
Bradley Mitchell is the expert writer for the About.com Wireless/Networking site and has an excellent, step by step tutorial on changing a router's default password:
Bradley's tutorial is specific to a popular Linksys router but the same general steps apply to just about every router, switch, and other network device out there.
If you're having problems changing your device's password and need more specific help, your hardware manufacturer's website should provide specific information for changing the password. Most manufacturers also have downloadable manuals available for each device model they sell which will also include directions for changing the password.
You can download your router, switch, or other network device's manual from the manufacturer's website which you can find in my List of Hardware Manufacturer Support Sites.
Note: If you don't know your device's default password then you obviously can't change it. See my Default Passwords List to find your router, switch, or other hardware's default password.
If you know the device's default password has been changed but you don't know the new password then you'll have to reset the device to factory defaults. You can usually do that by performing a specific sequence of actions on the hardware, details of which you can also find in your manual.
Once the network device has been reset, you can access it with the default login information and then change the password.