How can I fix "improperly installed" kext files?

I recently installed software for a Canon all-in-one printer and received these messages during installation:

(1)"/System/Library/Extensions/AppleUSBEthernetHost.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the products vendor for an update."

(2)" System/Library/Extensions/IomegaSAM.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the products vendor for an update."

The printer seems to be working okay but I'm concerned that other functions may be affected. I found a fix for the AppleUSBEthernetHost.kext at <When I installed updates, I got a message that said, "System extension ""/System/Library/Extensions/AppleUSBEthernetHost.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the products vendor for an update.">.

However: (1) After trashing that kext I couldn't find where to download iTunes 11.4 (the link took me to iTunes 12x, which is for OS 10.7, which I don't have), so I don't know how to proceed. (I put the corrupt kext file back in System/Library/Extensions.) (2) I assume I should try to perform the same fix with the /IomegaSAM.kext to correct the problem. However, I can't even find that kext.

Very low tech, here. Can anyone advise? Thanks!

PS: What's a kext?