Wow. When I looked for info about this on the web, I discovered that this seems to be an ancient device (by computer hardware standards) & the instructions for driver removal were written primarily for OS 10.1.x!
As you are probably aware, NetInfo Manager is no longer a part of OS X. (If necessary, see
"The end of Netinfo" Macworld article for more about this.) I'm not sure you actually need to create the ID & password as indicated in step 1 of the instructions -- this appears to be a badly explained reference to enabling & using the root (superuser) account in Terminal. If you do need to do this, in Leopard & above, you use the /System/Library/CoreServices/Directory Utility.app to do so. (One way to access this is explained in
Mac OS X 10.6 Help: Enabling the root user.)
However, you probably don't need to do this if you have already managed to move /System/Library/Extensions/PL2303.kext or /System/Library/Extensions/ProlificUsbSerial.kext to the trash. (I'm not sure what you mean about this being in a hidden folder -- the System/Library/Extensions/ folder should be visible from the Finder.) If you have enabled the root user, heed the warning in the help topic about logging out of & disabling the root user account when you do not need to use it.
Anyway, all you should need to do at this point is empty the trash & restart your Mac after disconnecting the adaptor from it. To be absolutely safe about this, you can first
Start up in Safe Mode, which disables non-essential extensions (kext files) & will ensure that the driver has not been loaded, then empty the trash, then restart normally after disconnecting the adaptor. However, I doubt that the driver has been loaded -- it is so old it probably is not Snow Leopard compatible to begin with.
Finally, go into System Preferences > Network & if you see a Prolific device in the list of network services on the left, just select it & use the minus button below the list to remove it. To make sure that no Prolific driver kext files remain in your Extensions folder, next click the plus button & make sure no Prolific network interface is listed in the "Interface:" popup on the sheet that appears for adding a new service. If none does, then you can be sure you have removed the relevant kext's. Note that you really don't have to do this -- the extension(s) won't cause any problems if they remain in the System/Library/Extensions/ folder but you may want to remove them for the sake of tidiness.
Message was edited by: R C-R
