Your Microsoft account will be deactivated for a year, then deleted. Within this period you could reactivate it.
For closing your complete Microsoft account, there is a different link, see the MSN entry on this site: http://www.accountkiller.com/en/delete-microsoft-account
Also see: http://windowslivehelp.com/solution.aspx?solutionid=baf3b47e-4618-49e1-ae2c-91e158a4cc76
If you can't find any contact info and still wish to ask something, for example a question about what exactly is deleted, about data retention, etc., you may contact the domain owners using this info.
If you signed up for Microsoft Live using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Microsoft Live. Click the icon below to find out how.