Well, it seems that your Windows files are corrupt or missing. To make sure of this, download IE7 and IE8. First install 7 and then 8 (8 can't be installed directly from IE6). If after these two installations, your system isn't working, then you can try to insert your Windows Cd and try to reinstall the missing files. If that doesn't work too, you will need to reinstall your os. Hope I helped.