Turbotax 2010 gives Error 123 every time during install

[dalearyous]

i have no idea how it happens, but my sister always seems to run into crazy problems with her computer. she has a desktop that is about a year old running windows 7. she had turbotax 2009 installed and went out and bought 2010 version of turbotax. during the installation i get an error 123. all of the turbotax bullshit fixes do not work. i have checked everything i can think of, even installed all missing windows updates including SP1. this is a shot in the dark but anyone have any bright ideas?