Having a problem software installations. what’s reason ?

Hi,
My computer operating system is Windows XP service pack-3. I have been suffering software installation problem. When I installed any program that time shown " runtime error ". Any software can't open there. Again and again tried but the result is same. Not only that I also used new XP installed, But the same message again are shown. What's reason ? I can't solve this problem. Please help me.
