[OS X 10.8.5] Software update error 102

I’m having trouble figuring out how to update this old Mac my friend gave me. Whenever I attempt to do a software update, I’ll get an error message saying “an error occurred while downloading the updates (102.)” I’ve already updated the apps individually under software updates, except for iTunes. I tried looking for threads and guides that might help, but I’m at a dead end. Can someone guide me on how to get past error 102 and do this software update?