Yahoo Messenger & Windows Live Msngr Won't Install

I've been reading on here and still haven't found any answers that can help
me.

My friend just bought a computer with Vista. He's had it 5 days. He tried to
install,
Windows Live Messenger, AIM, and Yahoo Messenger. Yahoo Messenger gets to 5
% installed, and then quits. It WILL NOT install at all. He's tried it about
70 times. Several different ways. I even sent him the download, AND a cd to
install it from. Nothing works.

Windows Live gets to 99% and stops. AIM was the only thing he got installed
(and it barely works), and he had to get a friend to do it from a flash
drive. Somehow he had the whole AIM on there and all he had to do was just
transfer the folder over. I tried this for him, with yahoo and that didnt
even work.

Can someone please help me? The only thing he has gotten to work RIGHT is
myspace IM, and that won't do web cams.

Thank you

Unless there is a security suite stopping the installation (Norton, McAfee,
etc) he should be able to download the install file, right click and choose
'run as administrator' and get all to install

Agreed, something is blocking the installations on that particular computer.
I installed both Windows Live Messenger and Yahoo messenger in Vista without
problems. Skype as well.
Some things to try; use run as administrator when starting the installation;
install the software from an administrator account; turn off 3rd party
security software before trying to install the messenger apps.

Copying over a program rarely works unless the software is self-contained,
otherwise there are Windows registry entries and system files that would be
missing.