Have you ever discovered that your internet doesn't work, but you have no idea what could be causing the problem? It isn't as simple as you might think...it could be your ISP, your cable or DSL modem, your router, your computer, your wireless signal, your security gateway (if you are a geek like me...), it could be almost anything. Luckily, there is a relatively painless and easy way to fix this. Are you ready for some Geekiness?

The first thing that you want to do is turn everything off. Once you have everything off, you are going to want to turn them on in the following order:
Your Modem (Cable or DSL). Turn it on and give it a couple of minutes to cycle through and establish a connection.
Your Router. Turn on your router and give it a minute to establish its connection.
Your Computer.

The logic behind this is that your computer can't connect to a network without the router booted and connected. The router can't establish a connection to the modem if it isn't booted up and connected.

Is it that simple? Probably not. So what do we do then? Let's look at some scenarios:

Modem doesn't connect to ISP
If this is the case, then either your modem is bad (unlikely) or there is a problem on your ISP's end (very likely). You should call your ISP and have them troubleshoot the problem with you. They should be able to do a line check over the phone and figure out if it is your hardware or if it is something on their end.
NOTE: I have Charter, and I love the fact that they are available 24 hours a day. They have been helpful for the most part. Occasionally you will come across a technician who will not be able to help. I came across this issue recently as they never hooked up the cable jack in my office and I (currently) have a long coax cable going to a splitter in my bedroom). I still need to get a tech over here. They have good service in my experience however, and I recommend them as an ISP.

Router can't connect to Modem
It may sound silly, but check all of your cabling. If it still doesn't work, then replace the cabling to one of your computers. Try again to power cycle your router (unplug power and plug it back in a minute later). Make sure to check problems at the router with a cabled connection. If you can't connect through a cabled connection, then bypass your router and plug your modem directly into your PC. If it works, then you know its your router. If it doesn't, then it may be something else. If it still doesn't connect then 99/100 times it will be a problem with your ISP. Contact them at this point.

Computer will not connect to router
With Windows XP and Windows Vista, if there is internet coming through the cable to your computer, it will find it. If you have an issue go to Control Panel-->Network and Sharing Center-->make sure that there are no red X's between your computer, your network, and the internet. If there is, right click and enable.

If you have a wireless connection problem, I will be writing a troubleshooting process for that in the next couple of days. This looks to be a very busy Geek week, so I should have it up in no more than three days.
Remember to hug a Geek. We need lovin' too.