I have this same problem, but when I go to the link provided by Ged, there is no link to CS5 products.
I am not a hard core user of Adobe products and don't, will never, need Creative Cloud, what I have in CS5 is all I need. This package is still being supported by Adobe otherwise the Update App would not be offering the supported downloads, but as you can imagine, they are of no use unless they will install.
I keep getting a prompt to download and each time I think, maybe this time it will work but get "There was an error downloading this update. Please quit and try again later" This has been going on for over a week now.
Is there an alternative source for these downloads?