Is it possible to do it in XP without using a load-balancing router?? For example, can we set a program to monitor whether the wireless network (the main connection) is down?? And if it is, disable the wireless one and enable the wired one so the system is internet-ready again within seconds.... Here we can assume that we do NOT need to enter passwords at all. I believe it should be totally possible and wonder why no one has ever mentioned this in the forum..... Any advice??
Even with a dual-WAN router this is not an easy problem. Simple test cases like disconnecting the cable from one modem and verifying that it switches to the backup are easy enough, but what happens more frequently in real usage is that one ISP becomes sluggish or sporadically unresponsive, without ever fully dropping the connection. This is much harder to detect and correct automatically. (Other threads on this topic can be found by searching for "dual wan".)
I believe that this will do what you want: http://www.nat32.com/ although I haven't used it myself, I have read about it before and saw it mentioned here in response to a question that looked similar to what you were asking (http://answers.google.com/answers/threadview?id=700234) I did have trouble finding much discussion about this (doing WAN-based failover in software on a Windows PC) which does seem surprising. Its probably because at the point someone is considering implementing WAN failover they are interested in configuring it to support multiple machines and thus a hardware-based solution is a better fit then a software solution that supports only the machine its running on. Hope this helps. Edit: Also found this: http://inetshaper.com/index.html, it may be helpful to look around for software based routing solutions as that is really what I think this amounts to. I also agree with akawesson, there are a lot of different failure cases and its hard to cover them all.
I hv enabled both the wireless and wired connections in XP. Now when one connection is down, the other one is used nearly immediately with just a few seconds of lag.... So no special hardware, router, software, macro, etc are needed.....
No... you need to enable the wired connection first if you prefer to use it as the main connection. If it is lost then it will switch to the wireless connection.