"Setup files corrupted"

[Steve Juniper]

Continuing problems. After GC refused to load after my using it with no 
problem for several years I followed the  one suggestion I got, removed 
GC entirely and downloaded 2.2.8 Portable via GnuCash.org. Installing 
also failed, giving msg: "Installer integrity check has failed... 
Download or damaged media." Then downloaded 2.2.9. Attempting to install 
it, after initial "Allow, I trust this program..." got msg: "The setup 
files are corrupted. Please obtain a new copy of the program." Thought 
maybe download problem so downloaded again. Same error. Downloaded to 
different computer. Same error. What can I do?

(Windows Vista on new HP desktop. XP on laptop. Somewhat slow connection 
(8-15 KB/sec) here in a rather remote place in the Andes.)

Steve J