Question : Multiple ISP load balancing

Hello,
Currently I have access to Internet through Local Area Network. But since this network often fails I plan to subscribe to a second Internet Service Provider. I will install another LAN card to connect to this backup provider. I want my outgoing traffic to be balanced between the two network interfaces, combining their speed and if one slows down or disconnects, the traffic must go thought the other one. I want the faster of the two connections to have higher priority. How can I do that? Please, recommend suitable system setting or software. I prefer to avoid expensive routers of other external hardware. My OS is Windows XP Pro SP2.

Answer : Multiple ISP load balancing

You don't need 2 adapters, as a matter of fact as a general rule, you cannot add a gateway address to 2 adapters, but you are right you can add 2 gateways to the same adapter, each pointing to it's own Internet connection. The two gateway addresses are assigned different "metrics" giving one priority over the other.
"In theory" it will use the gateway/route with the lowest metric. If that connection fails it will switch to the gateway with the next lowest metric.

However, a) as mentioned it won't switch back, b) this service is known to be flaky at best, it is not dependable and sometimes doesn't work at all, c) it will in no way "combine their speed" as you asked in your question, because only one connection is available at a time.

Not trying to be difficult, just it is a common question and to date I have seen no work-around.
--Rob