You can't change it online, it's configured locally in your wireless router, but you have not told us what you have so we can't help much. In general, you log into your wireless router's admin interface and change the password then save the new configuration. Common addresses for routers:
Common userids are "admin" and blank. Common passwords are "password", "admin", and "Comcast123". Consult your router's manual for the default userid and password for your particular model.
If you have one of the Comcast Xfinity Wireless Gateways, my condolences. The default user is "admin" and the default password is "password". If thos fail to work at http://10.0.0.1, then call the gateway support folks at 800-363-2416 and have them change it. Please note they ONLY support the Comcast provided gateways, if you have your own wireless router, read your manual.
Change what password? there are two and it's unclear which one you are changing or want to change. The gateway has an admin password (default is "password") and after you log in your can change that. But this has NO EFFECT WHATSOEVER on the wireless password, which is something else entirely. They are two different passwords so changing one has no effect on the other.
I, too, need assistance with my wireless password. I have two laptops and my ps3 connected and want to add another laptop and can't find the wireless password. Is there a way to look it up on the laptops that are currently connected?
Wow. I need the same help, but the response from reasd is so rude and flippant I would turn to another resource. It might seem amazing, reasd, but not everyone is as tech-savvy as you are. There's zero need for that tone of sarcasm and condescension in your response to people who need computer help. You need to find something else to do besides being a Most Valued Poster. Even if your advice is correct, I'm sorry, but you just make Comcast and yourself look real bad.
Do not let the queries here about 'which password do you mean' make you feel bad. The Comcast tech who installed my Arris TG862G router was just as indefinite as you were. He only told me about one of the two passwords --- the admin password not the Network Key. Hence, while he was here, he showed me how he was able to connect with his smartphone [showing me how he entered the admin password] but neglected to show me how he had previously configured in the Network Key. After he left, I had to figure out for myself what the Network Key was because he never told me, nor wrote it down on any of the paperwork he left.
I am going to assume that, by wifi password, you mean the Network Key. What is the Network Key? It is one of two identifiers a computer will need, at a minimum, to connect to the internet thru your router's wifi connection. Be advised, the words router, modem, and gateway tend to be used interchangeable in the home internetworking world.
To connect to my Comcast internet wifi connection, I had to configure my laptop with the Network Name and the Network Key. By default, the Network Name was 'Home-????', where '????' ends up being unique [more or less] to my router. There is a label on the bottom of my router which has both the Network Name [aka SSID] and the Network Key. If you call customer support, the tech should be able to check his records for the service you ordered and, from that, tell you what model router you have and how to obtain your Network Name and Network Key from it.
But, be advised, some techs are just as evasive about giving out such information as some here have been. Hence, he or she might choose to make you pay for a tech to come out and do what you could be walked thru doing over the phone. If that happened, get back here with the model number of your router [which will be labelled somewhere on it] and we'll see if we can walk you thru it.
Be advised that your computer may also require you to tell it what type of Network Key your router is using. Nowdays, as is the case with my router, the type of the Network Key is probably WPA2 Personal.
Some here have also mentioned what is the Admin password. The Admin password is not necessary to connect to the Internet. It is used to log into your router itself. Eventually, you will need it because otherwise some arrogant hacker with nothing better to do with his time and money may hack into your internet connection. The greater danger with that is not just that he will steal some of your available download speed, but that law enforcement officials tend to be mindless drones who might choose to arrest you for illegal material such as kiddie porn which was actually downloaded by some hacker thru your connection.
As mentioned elsewhere, by default, the admin login is typically 'admin' and the admin password is typically 'password'. Which is why one of the first things you should do, security wise, is log in and change the admin password to something else. Ditto for changing the Network Name and Network Key as well. While you are at it, you should also disable broadcasting of the Network Name, but I am now getting into more information than you are seeking at this time. Your Comcast installer could have done all of this when he was there. Actually, even if you installed your router yourself, the Comcast help desk tech might be able to configure all that for you thru their cable [aka DOCSIS] connection to your router.
But, alas, we live in a capitalist society where corporations would rather charge you yet more money to have someone else travel to your site and do for you what you could easily be walked thru doing over the phone.
I should perhaps apologize for my occasional soapbox griping. But I worked in the network engineering industry for 23 years. I know from personal observation how some people with a little bit more technical know-how get off on arrogantly dolely out information a crumb at a time to lesser experienced newbies as a way to stroke their own overinflated egos.
First off - THANK YOU!!! for the detail reply. Using the info you supplied I looked on the bottom of my wifi router (Netgear Wireless-N 150 model WNR1000v2) and found the admin/password and http site to login to my router. There I found the "missing" wifi password (so I can connect my Apple TV device to the wifi) as well as the admin password change to the router itself. These are now noted in a much safer place than my own memory!
So, thanks again - your assistance is greatly appreciated!