Q: iTunes was unable to load data class information from Sync Services

In the course of your troubleshooting to date, have you worked through the following document?

iTunes for Windows: "Unable to load data class" or "Unable to load provider data" sync services alert

Did so, still no-go.

Configuration:

----

Win 7 Pro x64 SP1

iTunes 10.7.0.21

iPhone 4S iOS 6.0 (10A403)

iPad 1 3G-WiFi 64G iOS 5.1.1 (9B206)

- fresh install W7 + updates

- fresh instal x64 iTunes (as offered on apple.com)

- direct USB PC-cable-iDevice (no USB hub)

- user account is Administrator class

- no error message under different Admin account, but also no data in library (same appleID used) :-(

- disabled ZoneAlarm (Checkpoint firewall) does not matter

- msconfig and limited start as mentioned in advanced troubleshooting - no resloution

- reinstall iTunes - no resolution

- iTunes display message from topic but after OK they sync at least something to/from iDevice

- iTunes also shows that they backed-up iDevice but Device Backups in Edit-Preferences-Devices shows nothing

- time to time shows "iTunes could not backup the iPhone XYZ because a session could not be started with the iPhone"

- Home Sharing turned off - no resolution, turned ON - still same + share not visible on iDevices

- previous installation of Windows + iTunes (older version, probably 10.6) - no problem

It just *doesn't* work!

Okay. On rare occasions the data class messages can be associated with LSP troubles, and LSP trouble is also a possible factor in back-up failures. So, just in case, try the following document:

Apple software on Windows: May see performance issues and blank iTunes Store

thanx for help, good point, lot of symptoms seen (low iTunes performance, sync crashes, no data from library seen by other users) but still no-go.

- used autoruns but only winsock shown is Apple

- used msconfig befor to troubleshoot possible conflicts, turned off everything except apple* bonjour*

- turned of even mobile helpers and then started those services manually

- library created from scratch on internal RAID field (iTunes were unable to read old library from that RAID datadisk)

all this haven't helped so far

- ocasional synces

- no backups

- no home shares

Message was edited by: xSilver iTunes - Help - Run Diagnostics always pass even sync tests

- used autoruns but only winsock shown is Apple

... okay. Pursuing the possibility a bit further. We might be looking at damage to the Winsock key(s) rather than a conflict.

If that's what is afoot, we might be able to clear the key(s) manually.

Let's try wiclee's instructions from the following post:

Re: i cannot connect to itunes on my laptop

did so, still nothing .. checked my other computer at work (which works normally)

- similar set of apps installed

- iTunes 10.7.0.21 also

- same Win 7 Pro SP1 x64 (different license key but both comps genuine)

- slightly different HW (home= built, work=DELL)

http://www.knowthenetwork.com/2011/09/overcoming-itunes-sync-issues-in-windows-7 /

THis works for win 7