Internet connection randomly shutting down

[actfray]

Several times a month, I will be unable to connect to the internet. I'll have no problem one minute, and then suddenly I'm offline. When I contact my IP (Comcast), I am told that there are no problems with my modem, and that there are no outtages in my area. I will unplug my router (to which I'm connected by a Linksys wireless adapter) for 30 seconds, and then plug it back in to reset it. (I was told to do this by Comcast). This does not solve the problem. My internet connection may come back within a few minutes on its own, or it will be down for an entire day before returning.

I run all my spyware programs regularly along with Norton AV, but this doesn't seem to affect the internet problem.

Is there anything else I can check when this occurs?

Windows XP home
Service Pack 1 (I had too many problems with service pack 2)
HP Pavillion a300n
2.6 ghz
256 ram

[DMR]

1. If possible, remove the router from the equation; plug the computer directly into the modem via an Ethernet cable. You will probably have to power down/up the modem and computer to get them to "talk" to each other. If your connection is stable with that configuration, the problem obviously lies with something in your internal (LAN) setup.

2. When the problem occurs, do the network link/activity lights on all devices indicate a good connection, or do they indicate a dropped/lost connection.

- check the status of your wireless adapter with it's setup/utility software.
- check the router's status in its setup utility; query the modem from the router if the router software has that ability.

3. Are you just losing the ability to browse the Internet, or do you lose all network functionality? When the problem occurs:

- Open a DOS box and run the following commands:

ping www.google.com
ping 66.102.7.147
ping the IP address of your router
ping the IP address of your computer
ping 127.0.0.1

What results do you get for each of the above pings?