access denied erroe - again

I'm trying ot instal SP2 on my daughter's XP Home
machine. It stops with an access denied erroe and
uninstalls. setuppai.log indicates three keys have
asscees problems and can't be
deleted: .AudioCD, .vnd.ms.Radio and .DVD. This happened
last week and I got a helpful response. I followed the
instructions in the KB article, and I can swear that
everyone has full control to each of those keys and every
subkey.

Here's a snippet form the log file (with one line before
and after) one of the offending sections:

#E197 Writing "C:\WINDOWS\INF\msmsgs.inf"
to "C:\WINDOWS\INF" is not an approved method of
installing INF files. Use a 'CopyINF' entry instead.

#-007 Deleting registry key HKCR\.AudioCD

#E033 Error 5: Access is denied.

#E065 Parsing DelReg section [Product.Del.Reg]
in "c:\windows\softwaredistribution\download\6ca7b3a8 efd5a
9b6f87fff395a2eb989\update\update.inf" failed. Error 5:
Access is denied.

#E064 Parsing install section
[ProductInstall.GlobalRegistryChanges.Install]
in "c:\windows\softwaredistribution\download\6ca7b3a8 efd5a
9b6f87fff395a2eb989\update\update.inf" failed. Error 5:
Access is denied.

#-007 Deleting registry key HKCR\.AudioCD

#E033 Error 5: Access is denied.

#E065 Parsing DelReg section [Product.Del.Reg]
in "c:\windows\softwaredistribution\download\6ca7b3a8 efd5a
9b6f87fff395a2eb989\update\update.inf" failed. Error 5:
Access is denied.

#E064 Parsing install section
[ProductInstall.GlobalRegistryChanges.Install]
in "c:\windows\softwaredistribution\download\6ca7b3a8 efd5a
9b6f87fff395a2eb989\update\update.inf" failed. Error 5:
Access is denied.
[2004/08/29 18:57:24 4092.1]

#-198 Command line processed:
C:\WINDOWS\$NtServicePackUninstall$\spuninst\spuni nst.exe
/~ -u -z

#E361 An unsigned or incorrectly signed
file "c:\windows\$ntservicepackuninstall$\spuninst\spun ins
t.inf" will be installed (Policy=Ignore). Error 1168:
Element not found.

There ar six of there, two for each key. Then the install
quits and uninstal begins.

Any ideas on what I could be doing wrong in the
permissions department? (I have two XP Pro machines -
could I copy secedit to this machine and reset the
permissions defaults automatically?)

Thanks