Theres no i386 folder in Windows 7, XP was the last edition to have that folder. Now, all OS files are located in the winsxs folder.
Coming to your problem, are these stock drivers
(that install by default with windows) or manually installed/updated drivers? Right click on each driver
with the yellow exclamation and update the driver, choose search automatically so that it goes online and looks up for updated drivers. That is by far the easiest way.
The best way though is to go to the OEM's site (if this is an OEM computer) or the manufacturer's website, locate the drivers for your devices and download them and install them. E.g. Realtek's site if you have a realtek audio card, broadcomm if thats what your network card is etc.
There are other tricks in the driver install business, first try out the above.