why does Messenger 2009 14.0.8064.0206 think its already installed when i try to instal? ETC....

why does messenger when i open and begin the installer think that i already have it installed when i personally uninstalled it before this...

why wouldnt the previous attempt ( when i was getting dns cache or likewise log-in/non-connection issues) when i got the sign in pop-up not let me swith to manual sign-in, there for even if it wasnt getting log-in errors, then would not have been able to sign me in anyway as it was stuck in automatic sign in with my old password, and would not give me opion to change to manual sign-in...

so i reinstalled a fresh installer after uninstalling that one, and it thinks that i have messenger installed and only gives me the option for photo gall', writer, tootbar.

what the hell is going on

my version ox XP is ver' 5.1 buil 2600.xpsp_adr.080814-1236: Service pack 3

the version of messenger is Messenger 2009 14.0.8064.0206

also, that search result thing below me is claiming falsly to have 338 answers, when its the same 5 questions more or less, repeated over and over