In addition to using an Internet security package, I always try to be up-to-date with my software installations to avoid security holes. So being a “good user”, I recently tried to install Windows XP Service Pack 3 and got a setup error “Access is denied”. What’s that? I never had problems installing Windows service packs so far! Checking Google for that error message returned more than 26,600 entries—Seems as if I’m not the only one with that issue . . .
Several hours and unsuccessful trials later, this is how I finally solved it:
I restored the default security settings with Microsoft’s Fix-It wizard.
It took some time for the tool to finish cleaning the settings, but after that the SP3 was successfully completed.