Windows installer problems in xp

Hello,
i can't install java, adobe, or webshots on my windows xp. funny thing it did install foxit reader. i get an error message windows installer can not be accessed. I downloaded hotfix from microsoft support. I carefully did all the steps that was on support it did not do anything. i went and renamed file first and that did not work. next i tried to reinstall windows installer did not work. i don't know what else to do. My system is 32bit. I went to system tab and got that info. please helllllp. java is used by many apps and need it.