Oh dear... i have had similar problems. Its a headache !
You might try downloading this tool -
http://www.download.com/Fresh-Diagno...ml?tag=lst-0-4 . That may help you discover what sound card you have installed... but you will no doubt discover as i have that you will need other drivers if you have formatted your computer.
Control panel , System, Hardware.. Device Manager - this may tell you something about your hardware, also if you have any yellow question marks you will need to find the drivers for that section.
Good Luck.