Cant backup because of Unknown Error (-20)

Try moving your already saved backups to another location then rebooting the computer. Reboot the iPhone as well (this part shouldn't matter, but it can't hurt).

And the solution, as explained above, is to remove the existing backup.

~/Library/Application Support/MobileSync/Backup/

When you next try to update the firmware on your iPhone, iTunes will create a new backup. Or you can force it to create one (Devices -> right-click -> backup). Chances are the existing one is corrupt in some way.

Titch13 said:

You probably cant help me with this, but where do I find the existing backup.

Click to expand...

dZp said:

~/Library/Application Support/MobileSync/Backup/

Click to expand...

.

Before we continue, what operating system are you using?

C:\Documents and Settings\USERNAME\Application Data\Apple Computer\MobileSync\Backup

because an unkown error occured (-20)

I am having the same problem but I am using Windows 7. Can anyone help me to locate the backup folder using thios opertating system? Thanks

grapes911 said:

C:\Documents and Settings\USERNAME\Application Data\Apple Computer\MobileSync\Backup

Click to expand...

I can't even find that on my computer! I'm haveing the same issue and I was going to fallow your advice, but I can't even locate my documents and settings folder. I'm using Vista as well.

If anyone cause help, I'd appreciate it!

~Enjo

Did this

I did this and it shows I have no backups to delete! please help im on windows 7

Hi guys !

Sorry ,to bug you guys, in your thread,but a have a problem :error19 ,i have a 3gs and i change my name carrier whit ibackupbot and i went on youtube to do it,
And now i cannot backup and sync
no more i need your help to put back the way i was .

And a lost everything in my phone because i did RESTORE on Itune, but now i try to have all the numbers ,in my girlfriend iphone how did i do that !!!
Thanks for everything!
ChebRx7

still got the same prob

hi i still have the unknown error 20 for backing up my iphone ( running on windows vista )

i tried both deleting the actual folder for mobile applications and also deleting the contents of the folder but leaving the folder empty - can you spot what im not doing correctly if this has worked for others?

thanks