Here's more information regarding the previous issue about knowing if the situation was caused with a recent security patch or not.

The situation has happened two more times since the previous post. That is a total of 5 times within about two days. On the last two times, I was able to get more data. When that happens, I check IPCONFIG. I see that my IP and the netmask is still there. But, the DHCP server has disappeared. PINGing my IP won't work. So, I have to restart the DHCP service. Once done, I see that IPCONFIG now shows all 0. So, I do IPCONFIG /renew. It starts the process but can't complete. Once interrupted, I see that a new IP has been given with the netmask. But, the DHCP address is not there. The Event Log then shows a failure to assign the DHCP address. Only a reboot resets everything.

Today, two more security patches have been issued. The first one was related to Windows 2000 and was making something about the TCPIP. It was not clear it if was related. Maybe Microsoft has treated that one has general. So, it's too soon right now to know if this is resolving the issue.

I called the Cable company. They say that all went fine for the last 170 hours on the Cable modem for the Internet. They assume the problem is local. In such situation, on their end, all is ok.

To resume, when that started to happen, I also installed SQL Server. However, if this would be a known problem with SQL Server, I guess we'd have heard of it since a while.