I have this problem too in WinXP, SP2, X86, With Internet Explorer 8.
I have 2 Browser installed : Firefox 25.0.1 and IE 8.
The flash player(14.0.0.125) has been installed successfully without any error. but Flash Player for IE8 dos'nt install and says : The Activex Control for Flash Player Could not be registered!
it is amazing that none of the profassionals in Adobe Co. can't help to solve this problem!