Vista - An error occurred duing the installtion of assembly ...

Error shot : http://muitommy.googlepages.com/Untitled.jpg

it's not only a single program's problem,
this happened when i installed adobe reader, acrobat 8, live messenger (but
with a different "public key token"), dreamweaver(error: msgs suppressed) ,
whenever i'm running windows installer (*.msi).

i can only solve this by creating a new account, and i can install the
program successfully for everyone in another account, for exp sibelius 5, but
the music fonts will be missing in my original account but not the new one.

Please someone kindly help me with this, and i don't want to transfer all
the info by creating a new account, this is troublesome, and i don't even
know if this will happen again!

Anything i can provide to help to solve the problems, tell me!!

Thank You Very Much!

post up some missing info:

i'm using Vista Ultimate
and my config in brief, (as i think it's not really matters)
Quad Q6600, 680i sli, 2G, 8800GT