I will try that next time the problem comes up.
tracert is going to tell you the path assuming you have a live connection. If you don't have a live connection, tracert isn't going to tell you anything other than "your connection is down." You can achieve the same result by pinging an IP address or domain name from a DOS prompt. It either works or it doesn't.
Before you do ANYTHING else - make sure you have the latest drivers for your network equipment. This includes your NIC and your router and anything else in the mix.
The only thing I've done to restore access is to do a full system restore to the previous day.
The problem you're describing sounds like network voodoo rather than your PC, but I'm not sure.
I'm using Comcast cable and the router was provided by them.
Okay, next time this happens, here is what I would do.
1) Check your cablemodem. Look to see that the right lights are flashing and/or solid. Models vary, so check its behavior when it's running right to get an idea what it should look like. If there are errors there, you've got an ISP problem.
2) Assuming that the cablemodem looks fine, I would next UNPLUG THE POWER FOR 30 SECONDS from the cablemodem. Power it back up.
3) Now - try to ping your router (if you have one in addition to the cablemodem.) Chances are the address is 192.168.1.1 or .1.2. It may be something else though. Got a router? Go to step 4.
If you do NOT have another router, go to a DOS prompt and type "ipconfig." You SHOULD get your public IP address and network settings from the ISP. If the info isn't there, you likely have an ISP/cablemodem problem.
4) If you can ping the router but not out to the net, you have a cablemodem problem or ISP problem. If you cannot ping your router, move to step 5.
5) Get a DOS prompt and ping 127.0.0.1. This is the "self ping" address of your network card. If that works, that tells you that your NIC is transmitting and receiving packets. It's not a full diagnostic, but it helps.
See where I'm going here? You are testing the various components to eliminate stuff that works from stuff that doesn't.
PM me if you want some other assistance.

I hope this helps.