'iPhone previously synced with computer' error when I connect to itunes

I also have been experiencing this issue since yesterday when I tried to upgrade to 2.0.1

Half way through installing the firmware update, my phone went nuts and kept disconnecting and reconnecting (hardware growler notifications) before throwing up an error (which I unhelpfully cannot recall now, but which I think was of the 0x800 'unknown error' variety). I cancelled the procedure and ejected the phone, before physically disconnecting it. Upon reconnecting, I was greeted with the same message as the original poster.

I went through the backup restore procedure successfully, but now every time I reconnect the phone to my computer it comes up with the same screen:

*An iPhone has been previously synced with this computer.*
*1. Set up as a new iPhone.*
*2. Restore from backup.*

I've been through the backup option at least three times now (takes an age) and each time I reconnect the phone I get the same message. I've rebooted my Mac, rebooted the iPhone, all to no avail. I'm very hesitant to try option 1 above, which I feel may solve the issue but I'll lose all the phone data in the process. I'm aware I could write it all down and re-input it, and some things, like my contacts, can just be re-synced from my Mac address book, but there's plenty of other stuff on there that is unique to the phone that I would not be able to get back on it easily.

If anyone has any insight on this matter it would be gratefully appreciated...

For the record I'm running an aluminium 20" iMac, Leopard 10.5.4 with an iPhone 3G.

I am having the same issue as of last night.
After I plugged the phone into my computer it started to update but wouldn't sync cuz it was almost completely full with "other." I tried everything and then just restored it to fix the problem.
I have all my contacts, apps and settings but no ringtones or music. When I tried to sync it again, it just came up with the restore screen, I have restored at least three times and the same thing keeps happening, no syncing, just a a restore screen.
Help! I want my music back.

Oh, its an original 8g iphone.

I too am having the same problem, except I have a iPhone 3G.

I have owned it for a week. I upgraded to version 2.01 several days ago and performed several syncs without any difficulty.

Tonight, I ran the battery quite low. On attempting to sync my iPhone with my Macbook, it gave me the "Set up your iPhone: an iPhone has been previously synced with this computer" message, with the same two options (Set up as new iPhone, or Restore from the backup).

I haven't tried either option yet. I did shut my iPhone down and boot it up again, to no avail -- the same message appears.

Help, anyone?

Replying to my own post last night -- restarting the iPhone and restarting the Macbook did not keep the "previously synced with computer" message from appearing when I reconnected to my computer.

I decided to click on "Set up as new phone." All of my songs, videos, podcasts were wiped from the phone. All of my apps, interestingly, remained. All of my photos that I had previously synced to the iPhone also remained on the iPhone -- however, the "sync photos with iPhone" box in iTunes was unchecked, and when I re-enabled it, it required me to wipe all of the photos off the iPhone before replacing them with the albums (from my computer) that I selected. I don't know if this behavior (selective retention) is a bug, but it's not clear to me why it would be designed to behave this way.

Anyone know what brings on this "iPhone previously synced with computer" message?

Is it a consequence of discharging to a very low battery state?

I get the same message, but in a slightly different scenario. I just got a replacement phone from Apple after my last one was encountering charging issues. The replacement came with the 1.1.4 software, which I upgraded to 2.0.1 and restored from my previous backup. Once I restored from the backup, it continued to tell me that another iPhone has been previously synced. It also lists two names in the list: iPhone and iFlan (which is what I named the original phone and again on upgrading the new one).

However, *syncing still works*. I am able to transfer music to the iPhone with no problems. A fix for this is certainly appreciated, since I still can't see the capacities or change sync settings as long as the error screen is up.

I had the same problem and tried restoring countless times. After each restore attempt, iTunes showed the 'iPhone previously synced with computer' message.

After spinning my wheels for hours, I tried the following steps from iPhone Atlas ( http://www.iphoneatlas.com/2007/08/24/special-report-troubleshooting-iphone-sync -problems#RecognizeMac), and everything is working again! Essentially, it seems you just need to delete then re-install iTunes.

1) Delete the following files:

a) The iTunes application (located in /Applications)
b) com.apple.iTunes.plist (from ~/Library/Preferences)
c) iTunes.pkg (from /Library/Receipts)
d) iTunesX.pkg (from /Library/Receipts)

2) Re-download the latest version of iTunes

I hope this helps someone. It worked for me.

Just tried this, but I still ended up in the same place: "iPhone previously synced with computer"

Setting up as a new phone made me have to re-sync all my music, etc., but now it works.

-Chris

I had a similar experience this morning--it's a first for me.
It began the sync but then I got an error message that it couldn't be done. Something to the
effect that it couldn't find the volume. I did notice the sync rotating wheel in the left hand column stopped spinning before the error message. Also I x'd out of the back up process. It did this 2x.

I held down the home button and lock button until I saw the apple logo and then plugged in the USB.
It seemed to fix it.

I just set mine up as a new phone, it didn't even try to change anything on the phone itself, it just fixed the problem in iTunes and everything works fine now. It's about that time for Apple to change their "Just works" statement to something more realistic;)

I think that this:
An iPhone has been previously synced with this computer.
1. Set up as a new iPhone.
2. Restore from backup.

means that if you choose the first option, then itunes will not save over the old backup. choosing "Set up as a new iPhone" in this case is like selecting "Save As..." instead of "Save"

I just had to choose that now after doing a hard restore this morning. i had to restore the phone with RECOVERY MODE in order to get past the bootup "apple logo" screen this morning. when I did, none of my media or pictures were on there, but all of the apps worked again (all of the downloaded apps crahsed immediately upon opening. when i plugged the phone back in, it gave me this option of "Set up as a new iPhone" or restore from backup. i didnt wanna choose option #2 because i just got my apps working again and started puttin in the passwords....... so i chose "Set up as a new iPhone" and all of my previously selected videos, photos apps and ringtones are still selected to begin syncing again.

I am having the same issue outlined above. My computer continues to say "An iPhone has previously been synced with this computer" I have tried to choose from a previous back-up but I continue to get the screen no matter how many times I try. I know setting up a new phone will work however that means all of my settings, all of my SMS, all of my weather, stocks, bookmarks, etc are gone!! I tried all of the above suggestions but to no avail. SOMEONE PLEASE HELP!!

I was advised by Apple tech support to go ahead and choose "set up new iphone". I had problems syncing some applications after I setup my iphone, but was also advised to delete them and re-download the applications.

My iphone is now back to normal, but this new update caused me to lose a lot of time today.

Over the past few weeks, I've been having issues with my phone, mostly a lag on the keyboard and scrolling through contacts. So, I decided to restore (after installing 2.0.1). All seemed to be fine with the phone, but every time I connected it to itunes, I kept getting the restore screen. After 3 attempts, I have decided to try the "Set up as new phone" option. It is currently in progress, so I will let you know how it works out...