Hi all! I am desperately seeking help regarding fixing my internet connection. I currently have my home PC connected to a Lynksys Modem and have Comcast high speed internet. We bought the computer in 2008 and have never had a problem until about 2 weeks ago. We went to access the internet and the dreaded error message appeared: Limited or No Connectivity. Until 2 weeks ago, I knew nothing about computer networking and still honestly know very little. I have searched around on the forums and have no clue how to fix this problem. These are the steps that I have done so far:

1) Spoke to Comcast in-depth and had them come out to confirm that it wasn't a problem with the service.
2) Purchased a new modem, registered it, and confirmed it is getting a strong signal
3) Did a full system scan in Command Prompt and confirmed that nothing is corrupt
4) Uninstalled Norton Security in case it was a firewall problem
5) Attempted to manually enter a new IP address and Subnet Mask (then computer said wrong IP configuration)

So, I am completely in need of desperate help with this right now. I have read in other forums that people have brought their computers into the Geek Squad at Best Buy, have paid $200 to try to fix this problem, and it still didn't get resolved. Here is all of my information from my ipconfig/all

Windows IP Configuration
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix
Link-Local IPv6 Address: fe80::582a:11d8:1911:c7a9%8
Autoconfiguration IPv4 Address: 169.254.199.169
Subnet Mask: 255.255.000

Also, I have done a ipconfig/release, shut down the computer, and then did an ipconfig/renew to no avail.

Any help would be sooooo greatly appreciated!!!!!!! Thank you, Thank you, Thank you!!!

unplug and disconnect all network related hardware (modem,router, etc.). wait 10 seconds, then reconnect everything (cable modem first). then reboot.
if that doesnt work, go to device manager and uninstall the network adapter, then reboot and let windows reinstall it. if you use a wireless adapter, make sure it is enabled.
before anything, click the network icon (near the clock) and make sure it is set to automatically connect to your preferred network.