If you don’t use your Windows Live Hotmail account regularly, be aware that it will be deleted after some time of inactivity. You have to use your Hotmail account on the regular basis but in case If your Hotmail account expired you can contact Hotmail support center.
People who try to send email to an inactive Windows Live Hotmail account get their message bounced back with a delivery failure. You can still use your account name and password to login to Windows Live.
After 360 days (five days short of a typical year) of inactivity, a Windows Live Hotmail account is permanently deleted. If you don’t use your Windows Live ID (which is your Windows Live Hotmail email address) for 365 days (about a year), it, too, can be permanently deleted. Somebody else can take your Windows Live Hotmail address so that Hotmail account expired is reduced.
Or you can follow the steps inorder to reactivate your Hotmail.com expired account using this link:http://email.about.com/od/windowslivehotmailtips/qt/Know_When_Your_Windows_Live_Hotmail_Account_Becomes_Inactive.htm