yahoo messenger  is unable to download files needed for installation.

please check firewall settings and retry again

Hi

You posted in the server forum not the windows 7/8 forum.

Which browser are you using? IE or chrome? can you check if your AV or firewall is allowing downloads? also check if downloads are enabled in the security settings in IE.

Disable the firewall/UAC, reboot and try the download again.

Hi,

As it has been a while since Ed provided a reply, I would like to know if the issue still exists.

Sometimes downloading issue is just a temp issue and could be fixed with a reboot.

If issue still exists, please test to disable any security programs like antivirus program, firewall etc as well as Windows Firewall. 

Also if it is a client system (Windows 7/8/8.1), you could post to related forum as this forum is mainly focus on Windows Server system. 

Windows 7

http://social.technet.microsoft.com/Forums/en-US/home?category=w7itpro

Windows 8

http://social.technet.microsoft.com/Forums/en-US/home?category=w8itpro