In Windows XP, some background processes can cause issues that may prevent applications such as iTunes and QuickTime Player from working correctly, opening, or even installing. Learn how you might resolve these conflicts by disabling some items using the System Configuration Utility (MSCONFIG).

Learn more about TCP and UDP ports used by Apple products, such as Mac OS X, Mac OS X Server, AppleShare IP, Network Assistant, Apple Remote Desktop, Macintosh Manager, and MobileMe. Many of these are referred to as "well known" industry standard ports.
Note: Mac OS X v10.5 and later includes the Application Firewall, which is different from a port-based firewall.

Apple asks customers to help improve the iOS by occasionally providing diagnostic and usage information. Apple collects this information anonymously.
By default, opting in is a one-time decision. If you’d like to change your decision, you can reset warnings so that you will be asked again.

iCal, iOS 4, and MobileMe all offer a Birthdays Calendar. This calendar is automatically generated from birthday information found in your Address Book contacts. Contacts whose first birthday is more than 77 years ago do not display when viewed in the Birthdays Calendar on an iOS Device, such as an iPhone, iPod touch, or iPad.  
The Birthdays Calendar can be synced via cable (USB) in iOS 4 or earlier versions. In iOS 4, the Birthday Calendar is available directly on the device, either from contacts stored on the iOS Device or synced with MobileMe. This issue occurs regardless of whether the Birthdays Calendar was created on the iOS Device or synced to it via MobileMe or iTunes.

After setting up an email account, you may find that Mail loads message titles but not the message body previews or that mail receives blank messages:

With preview
Without preview
Blank message