how to find where did the downloaded driver go

[Abhishek Dixit]

I am in a stage where I am frequently formatting my computer.My laptop
needs some kind of properietary wifi driver.
After installation of Ubuntu I go to control panel and enable the
available drivers for this machine.
Where it downloads or enables STA Broadcomm driver.I want to know how
do find out what changes does it do or where does it keeps the
downloaded  file since I have to format my laptop
 many many times so I want to copy it in a USB.That will save some
time at my end.

-- 
Regards
Abhi