I am having trouble installing. I am having trouble installing yahoo messenger for windows vista

Question

I am having trouble installing yahoo messenger for windows vista on my computer. I can download it all fine then click run.It downloads fine. Im just having trouble installing it. When it prompts me to install it goes through the whole process and at the end the computer wont install it and says that it was installed incorrectly. Ive tried turning off the UAC on my computer. And Ive tried saving it to my desktop and running it that way. Ive even tried to download straight from the yahoo site then install and it still wont work. Ive even turned off my firewalls the fire wall to my antivirus and the one that comes with the computer. Something must be wrong with the settings on my computer. Do you think you can help me figure out what I need to do to download yahoo messenger for vista?