Web Forms :: Need Vb.net Website Spider

I have been Googling this, and I don't see much. I just want some code that uses multi-threading so it's fast. The bot should start on the home page, spider all the links, store the local and non external links, then spider all those links it just found simultaneously. This requires multi-threading. It has to test each link at the same time. I just need 3 clicks off the home page. So it's gets all the home page links, then it spiders each one of the those links found and adds all other local links found to the list. Remove the dupllicates on the list and sort the list.

That gives me a list of webpages that without fail will be indexed in Google, etc. When someone inputs a web page url into a text box and clicks a button, this should happen in a matter of seconds. Where can I find this code for free? This really important for my site.