It should be listed in Start/All Programs. If not then it may have been turned off, Go to Control Panel/Programs and click 'Turn Windows Features On and Off' and make sure it is checked there.
You may have to reboot to get it to show up in the Start menu.
Then of course you will have to set it up. Having never used an external card I'm not sure how you go about that but I guess you'll figure it out.
In there is a setting which by default has incoming faxes turned off, at least that's how it was on mine, that is probably what needs changing.
Windows Fax and Scan Shortcut - Create