I have three IIS/ASP web sites on one hosting account.

A couple of months back, i asked my hosting administrator to redirect non-"www" pages to "www" pages on all three sites to avoid google's duplicate content issues.

Now i dont know how they did it, but my request was carried out and it seemed to be working ok. Then some time later, i noted that two of my websites started to fall in search engine rankings rapidly and google stopped indexing these sites altogether.

A SEO friend suggested that i check upon the server reponse of these sites. When i checked my logs, i learned that these two sites were being 302 redirected instead of the correct 301 redirect. The site which is still doing ok is also the main site of my hosting account and seems to be getting 301 redirected, so no problems there.

I asked my hosts to correct this issue, but they do not know how to resolve it. Can anybody describe in a step-by-step form, the things my host has to do to setup 301 redirect properly for these sites?