As we all know Microsoft has released the final version of Windows XP SP3 to public and its available via Automatic Updates, Windows Updates and Downloads Center.
Earlier we posted about it at following link:
Windows XP SP3 RTM Available on Windows Update, Automatic Update and Download Center
You can download the SP3 from the above mentioned link.

A few people are facing a problem while installing SP3. Whenever they try to install it, Windows shows following error message:
Service Pack 3 setup error. Access is denied.
OR
Service Pack 3 setup error. Service Pack installation did not complete.
If you are also facing the same problem, then follow these simple steps and your problem should be solved:
1. Download and install the Subinacl.exe file from here.
2. Open Notepad and paste following code:
cd /d "%ProgramFiles%\Windows Resource Kits\Tools"
subinacl /subkeyreg HKEY_LOCAL_MACHINE /grant=administrators=f /grant=system=f
subinacl /subkeyreg HKEY_CURRENT_USER /grant=administrators=f /grant=system=f
subinacl /subkeyreg HKEY_CLASSES_ROOT /grant=administrators=f /grant=system=f
subinacl /subdirectories %SystemDrive% /grant=administrators=f /grant=system=f
subinacl /subdirectories %windir%\*.* /grant=administrators=f /grant=system=f
secedit /configure /cfg %windir%\inf\defltbase.inf /db defltbase.sdb /verbose
3. Save the file with name "SP3.bat".
4. Now right-click on the file and select "Run as administrator". It might take some time to complete.
5. After completion, restart your system and now you should be able to install SP3.
This article was posted by VG in following section: Troubleshooting, Windows XP.
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Nurse Ratchet
I was one of those "really stuck" PCs. Had tried several different things. Your solution finally did it! Thanks so much...
Stogie Bear
This easy fix worked great for me...
(If you don't get the "Run as administrator" option then simply double click on the file.)
The resulting dos window may look scary as it whisks through your computer, but it's all part of the grand plan!
thanks for this... (Came in #1 in google too.)
Rick
How do you know when the SP3.bat file has finished running? Mine seems to have been running and changing files for the last half hour!
OLYMP
!!! DOES SP3 installation reset the registry ??????
Sam Danziger
Thanks a lot! That worked great.
Pete
Thanks to PJ, I followed your steps listed here and successfully installed SP3 on both of my machines...BTW I also had SpySweeper as others here have posted which may have been the prob
PR
This fix worked perfectly for one machine that was returning the 'Access is denied' error. Problem solved using the Subinacl.exe and SP3.bat.
Ken Z
Subinacl.exe and your batch filew SP3.bat worked great. Thank you! Thank you!
:?: Do their actions need to be reversed to prevent any security hole as they must have opened up some previously denied access? Is there a risk to be aware of?
VG
^^ No. There is no risk. Glad to help you.
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