回复：重装电脑XP后,没声音,不能上网,Other devices下都是黄色问号

I would suggest you download the ethernet controller from Dell's website using another computer with web access and install it on your "disabled" computer. Once your internet connection is up, the rest is quite simple. Just go to Dell's website, retrieve any relevant files that did not get installed from your system CD, and install them one by one. I feel the system CD that came with your computer was not up to date and you cannot count on MS for service packs as MS stopped Windows XP support a while back.