Where I can get third party software for fax & scan.
Scanning software usually comes with your scanner, and you don't
normally need anything else. The more serious lack is fax software.
Google will find you many choices.
What will be the cost if
I upgrade to Window Vista Business or other upgrade
You need Vista Business or Ultimate. The cost depends on where you buy
it. Google is again a good source for finding choices, but all are
almost certainly greater than the cost of fax software. I wouldn't
consider upgrading just for this.
that have fax & scan soft
wire.
Also consider the low-tech solution of buying a standalone fax
machine. They can often be bought on sale for as little as $20 or so,
and that may be your best and most economical choice.