Jet engine 4.0 Service Pack 8

I'm doing some testing on installing and uninstall Jet4
SP8 (KB837001). When I try and do an uninstall from
Windows XP Pro I get a message saying it can't find a
file. It starts with dao360.dll but if I skip that file
it ends up saying the same thing for all the files it's
trying to restore from c:\winnt\$NtUninstallKB837001$.
The log file KB837001Uninst.log shows the following:

MySetupDecompressOrCopyFile: SetupDecompressOrCopyFile
from source C:\winnt\$NtUninstallKB837001$\dao360.dll to
target c:\program files\common files\microsoft
shared\dao\dao360.dll failed: 0x5
***

Service Pack Setup encountered an error: 0x5
***

MySetupDecompressOrCopyFile: SetupDecompressOrCopyFile
from source C:\winnt\$NtUninstallKB837001$\dao360.dll to
target c:\program files\common files\microsoft
shared\dao\uninst0.tmp failed: 0x5
***

Service Pack Setup encountered an error: 0x5
***

MyMoveFileEx: MySetupDecompressOrCopyFile failed: 0x5


Does anybody have any idea what this error is and what
causes it? I don't get the problem when trying to
uninstall from Win2k Pro.