HELP, Please!

I know that there are any number of you who have expertise on this.

I have DSL wired to my office, a dedicated line. Since last Friday I have not been able to reach any Internet sites with any browsers. The message that I get at the bottom of IE is

//C:\WINNT\system32\shdoclc.dll/dnserror.htm

All of the hardware seems to be in working order. (I'm using the old dialup modem to connect right now--talk about SLOW!) I've scoured settings and diagnostic programs and cannot find any indication that this culprit is anything but a software setting, but I'm darned if I can find it.

I've searched on "DNSerror" and found a page that SEEMS to have the answer, but I need help interpreting it:
http://inetexplorer.mvps.org/answers.htm . A little more than halfway down this long page is the sentence Can't display page (Server or DNS error) or "Internet Explorer could not open the search page" and this discusses it.

I use Win2000Pro on a Hewlett-Packard Pavilion 9870, and honestly, it has been so long since I've used DOS I don't remember if I have a DOS-like feature in here. I went through using the settings in IE and deleted my history (recent pages, etc.) and cookies. I have to reset a bunch of them (including Mudcat, as I realized when I started this thread). I realize this isn't the same thing as running the DOS command and truly deleting all of this stuff.

Any ideas? I'll probably think of things I forgot and add them in later, but any help will be appreciated.

SRS