Hello Cheryl,
See MS Knowledge Base article 949377
Error message when you try to install Windows XP Service Pack 3: "Access is denied" or “Service Pack installation did not complete”
http://support.microsoft.com/kb/949377
For pre and post service pack installation guidelines, see this page at AumHa.org
WINDOWS XP SERVICE PACK 2 FAQs & BEST PRACTICES
http://aumha.org/win5/a/sp2faq.htm
While the title and notes refer to SP2, it generally applies to SP3 as well.
I see you mention getting service pack 2. You may as well go with service pack 3 directly, since SP3 is cumulative, and includes all fixes from prior service packs.
If in any way you suspect a malware problem, make sure you have done complete virus and malware checks beforehand.
Pre-Installation Recommendations
http://aumha.net/viewtopic.php?t=7260
--
Maurice Naggar
MS-MVP (Windows Client) , Aumha.net VSOP , DTS-L
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"Cheryl" <Cheryl@discussions.microsoft.com> wrote in message news:9F8405CC-093E-4561-BDBE-1B3F8D382641@microsoft.com...
> Hello,
> I am trying to install Service Pack 2 on a home pc. I received the above
> error. I checked the forums and there are too many answers and I do not know
> what to do first. I know I am very late installing this software. Can anyone
> advise what to do first? I don't know if it is a network problem, virus
> software or registry issue, or something else.
>
> My daughter has the new ipod Nano and can't download music unless we have
> the latest iTunes, which requires Service Pack 2. Please advise. Thank you.
> Cheryl