My internet stopped working? DHCP Client doing wierd things?

[Hack&Lube]

Okay I usually know what I'm doing but this has me totally stumped.

My main computer usually connects to the internet via ethernet cable to my wireless router (which provides wireless for a laptop). Last night, my internet suddenly stopped working on my main computer. I noticed that in network connections, there were usually 3 icons, wireless internet (disabled for my main computer since it's connected via ethernet), local area network, and high-speed internet connection/internet gateway.

The high-speed connection/gateway icon disappeared and now there is only LAN. The LAN says it's connected but I can't even connect to my router (192.168.2.1) through internet explorer. I log into my router via wireless and see the DHCP is assigning a proper IP to my main computer but for some reason, the main computer can't see or access the router through the wired LAN.

I thought that perhaps my new router was busted so I connected my laptop to the router via ethernet cable but wow, it worked (and I got the high-speed internet connection/internet gateway icon). So my laptop can work on the wired LAN...So I thought perhaps the network controller or ethernet port on my main computer is busted...so I installed/uninstalled it, updated drivers, used the create new connection/home network setup wizard a few times, etc. I then disconnected it from the router and plugged it directly into the cable modem - bam! I have internet.

So why does my main computer work if I plug it directly into the modem but not if it's plugged into the router all of a sudden? It worked fine like this for over a year. Other computer can be plugged into the router and work fine. I have no idea what's going on. I even plugged in a wireless USB network adapter to my main computer and tried it out and that works for connecting wirelessly. I just can't connect to the router with my main computer via ethernet and I've tried 3 different cables - that's not the issue as again, it works when plugged straight into the modem.

***I tried to repair the connection but it told me it couldn't clear the DNS so I went to command prompt and did an ipconfig /flushdns and it failed. I poked around and discovered that for some reason, my DHCP Client in services.msc was stopped (what would cause this to happen? Some kind of malware? I was just surfing the internet one second and the next, no internet). I turned it back to automatic and started it, restarted computer, etc. but I still have the same problem. I noticed that the logon for the DHCP Client was also set as network service with a strange long password I didn't recognize. Shouldn't this be a local service???

Under ipconfig, the DNS suffix is my internet provider and everything else seems to checkout fine, except that I can't even ping my router, it times out.

[psicodude]

Anything in the event viewer?

You could try running the network wizard thing again too, although it rarely helps.