I have a site which was ruined by a virus.Thats why I deleted it completely.I decided to restart it ina new way. But now webmaster tools is showing hundreds of 404 crawl errors.How can I tell google that I have removed those links and want to start my site in a new way?
Google has clear instructions [google.co.uk] for how to get removed from their index. Follow that and you'll find that it works.