I could download the w3cschools website only AFTER I have changed the httrack
signature to Internet Explorer 5.5. wget under my Linux also didn't worked. I
belive they do a server side check to see the browser. Is this legal?
The signature I used was:
Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.1; .NET CLR 1.1.4322)

I hope it helps.