Ok, so in order to ping another computer you need some information first. You need to know the IP address of the other machine, and you need to know the commands in order to do the pinging. Here is a step by step with screen shots I just slammed together for you.
Step 1.
Bring up the run dialog box by hitting <Windows key + R> or by going to start>run. Then type in the word "cmd" without quotes and hit enter.
Step 2.
After you hit enter a black terminal will pop up. From here you can enter commands and such. This is very similar to working in DOS.
Step 3.
From this command promt we want to type in the command "ipconfig" and hit enter we can now see what our current private IP address is where it says IP Address............. xxx.xxx.x.xx
Note: You want to do this on some other machine besides your desktop. Because we want to find out the IP of a seperate computer so we can use the desktop to ping it. I hope that makes sense.
Step 4.
Now that we have the IP address of the host machine we want to ping, write it down or memorize it or something. Now go to the desktop with the bad connection. Bring up the command promt as you did in steps 1 & 2. Except now type in "ping" instead of "ipconfig" and follow the word ping with the IP address you wrote down.
As you see I have a 0% loss with no packets being dropped and no collisions. If you have something else, let us know.
