TechARP has published an article about the 'secret pre-release details; for the upcoming Service Pack. It's definitely interesting reading.

Microsoft identified these as the top 5 reasons (and their knowledge base articles) for Service Pack 3 installation failures.

#1 : Prerequisite Failures
Windows XP Service Pack 3 installation fails with an error message, and the following error is logged in the service pack installation log: "8007F0F4 - STATUS_PREREQUISITE_FAILED". It can be due to :
- AC Power
- Incompatible applications / versions (Microsoft Shared Computer Toolkit, RDP 6.0 MUI Pack, Windows Fundamentals for Legacy PCs, x64 Edition, MCE 2002/2003, Windows Embedded for Point of Service)
Impact : Low - most of these issues are by design or can be self-resolved by the user by obtaining the correct update package.
KB Content : KB949388, KB950717

#2 : RPC Call Failed
Generic failure which is usually symptomatic of another problem
Impact : Low - issue can generally be resolved by reattempting installation or following general troubleshooting guidelines.
KB Content : KB950717, KB950718

#3 : Access Denied
When you try to install Windows XP Service Pack 3, you get one of these error messages :
- "Access is denied"
- "Service Pack installation did not complete"
Failure typically caused by antivirus or other 3rd party security products which may lock system files. Additionally Registry ACL issues can cause access denied.
Impact : Low - Issues can be easily resolved by disabling AV or modifying registry ACLs
KB Content : KB949377, KB950717

#4 : Disk Space Failures
You get one of these error messages when you try to install Windows XP Service Pack 3 :
- "You do not have enough free disk space on %SystemDrive% to install Service Pack 3"
- "You do not have enough free disk space on %SystemDrive% to archive the uninstall files"
SP3 can require up to 1.3GB of free space if system restore is enabled
Impact : Low - issue can be resolved by freeing up additional space
KB Content : KB949385, KB 949375, KB950717

#5 : Download Failures
Failure to download SP3 via Download Center. When you try to install Windows XP Service Pack 3 from Windows Update, the installation fails, and an error code is logged in the Windows Update log file.
Impact : Low - download failures are typically implicit and generally do not have heavy reoccurrence. Can also be caused due to system file changes after the creation of the express package.
KB Content : KB949386, KB950717

Issues With Internet Explorer
Issue #1 : You cannot uninstall Internet Explorer 7 or Internet Explorer 8 Beta 1 after you install Windows XP Service Pack 3
Impact : Low - in the case of Internet Explorer 8 Beta, a Windows Update detection script will be in place. It will not offer SP3 to IE8 beta users.
KB Content : KB950719
Issue #2 : After you upgrade to Windows XP Service Pack 3 (SP3), when you double-click the Internet Explorer 7 icon on your desktop, Internet Explorer does not open and a new shortcut is created. If you click more times on the Internet Explorer icon, more Internet Explorer shortcuts are created. If you click the Internet Explorer shortcuts that are created, nothing occurs.
Impact : Low - this only impacts users which perform an upgrade to SP3 using a Full Product CD (integrated).
KB Content : KB950721

Third Party Wireless Networking Drivers
Windows XP SP3 introduces a new .dll file that is named Wlanapi.dll. Certain device driver installations for some third-party wireless network adapters also install a Wlanapi.dll which will be replaced by SP3 resulting in errors.
This error message will appear during every restart after you install Windows XP Service Pack 3 : "The procedure entry point apsSearchInterface could not be located in the dynamic link library wlanapi.dll"
Impact : Low - Obtaining updated drivers for the WLAN device resolves this issue
KB Content : KB 950720