It is possible that your anti-virus software is corrupting the downloaded files or otherwise interfering with downloading files by Firefox.<br /> You can try to disable the real-time (live) scanning of files in your anti-virus software temporarily to see if that makes downloading work.<br /> Do not forget to re-enable the scanning in your anti-virus software after you are finished with downloading and installing.<br /> See http://kb.mozillazine.org/Unable_to_save_or_download_files (Disable virus scanning in Firefox preferences - Windows) ---- Your plugins list shows outdated plugin(s) with known security and stability risks. *Shockwave Flash 8.0 r22 *Java Plug-in 1.5.0_01 for Netscape Navigator (DLL Helper) Update the [[Java]] plugin to the latest version. *http://java.sun.com/javase/downloads/index.jsp#jdk (you need JRE) Update the [[Flash]] plugin to the latest version. *http://www.adobe.com/software/flash/about/