If you’re trying to install Apple’s new iPhone 2.0 software update this morning, it’s very likely you’re seeing the “unknown error occurred (-4)” message.
The problem isn’t the update itself, which does download and install, it’s the re-activation that has to occur via the iTunes Store. There are heavy reports from around that world stating that the activation servers are just overwhelmed.
Unfortunately, the result of this inability to communicate with the server leaves the process incomplete, and the iPhone is totally bricked (broken, kaput, useless). It will not function until the server load is resolved and iTunes can reactivate your iPhone.
Once you see the error message, iTunes stops trying to communicate with the store. To get it started again, click on something else in the iTunes sidebar like, “Music”, and then click on the iPhone again. Doing this makes iTunes try again. Unfortunately, you’ll have to keep doing this until it works. I’ve been trying for about an hour. :(
UPDATE: It took about 3 hours, but iTunes did eventually reactivate my iPhone. I’ll be sharing my impressions of the new software in a later post.