When I try to update from CS5 menu, I get an error that they did not install

I am running CS5 on Windows 8.1.  When I try to update from CS5 menu, it appears updates are downloading, but then I get an error that they did not install (no error number), and contact customer support.  When I click on that I get a discussion about incorret serial number.  I deactivated, then reactivated, get same results.