Before you try to use it wirelessly, you should hard wire the router into your network. Basically, just run the incoming ethernet cable into your cable modem and then run an additional ethernet cable from the modem to the input port on your router. Then you can connect your router to your laptop with another cable. It doesn’t matter which of the 4 ports you use.
Once you do that, you need to go into your network settings and make sure you’re wireless and LAN connections are both enabled. Actually, I’d do that before even making the connections. At this point, even though you’re using the router, you’re not Wi-Fi so you should be able to get online. If you can do that, you need to get into your online Linksys router settings. In your info that came with the router, you’ll see the IP addy for doing so. Usually something like 192.168.0.0. And I think the default username is “Admin” and default password is “password” for Linksys. Once you’re in, check over all your settings and completely disable your encryption. Until you’re able to actually get a Wi-Fi signal on an unsecure network, don’t enable WEP/WPA.
Make sure all of your settings look okay but most of the default settings, aside from security, are what you want. Once you do this, you can save/exit out. And then you can try to unplug the ethernet from your laptop and try to get on. You may want to reset both your router and cable modem. TW’s modems are VERY glitchy when it comes to making changes and often need a reset to work properly. You can just unplug them for about 10-30 seconds and plug back in.
Does your laptop have a built-in Wi-Fi card? If so, you need to make sure you have no confliction with your laptop’s wireless software and Windows Wi-Fi management. I had someone with a problem similar to yours (same router) and that was their problem.
Another question: Are you able to see your SSID when you “view available networks?” If so, are you prompted to enter a password? I can tell you that with Linksys, you may have trouble logging in if you enter the passphrase. I’ve come across several Linksys routers that will only connect when you enter the 26 alpha/numeric string instead of the passphrase, which is used to generate those 26 characters.
Hard to diagnose it without knowing exactly what you’re seeing. I did notice you said you can’t get a signal when you incorporate the router, via hardwire. I know it sounds overly simplistic, but if you haven’t tried resetting the modem/router after making that connection, then I would try that first. With TW, more often than not, a cable modem reset will fix the bug. And don’t use USB to connect your modem. Always seems to be a problem with TW’s modems via USB. After that, I’d check your network settings via Control Panel to make sure you’re enabled. I don’t think you’re having an encryption issue if you can’t get on with it hardwired.
Network fixes are easy to accomplish in person but a pain via phone/online chat.