Especially when you delete multiple emails at once, it is easy to accidentally move to the Trash (the Hotmail Deleted items folder) an email message you did not mean to get rid of. The Deleted email folder in your Windows Live Hotmail account works like a safety net: emails you delete are actually only moved there, and will stay in that folder until you either manually empty the trash, or until a certain period of time has elapsed (Hotmail will automatically purge the Deleted folder from any emails).
You can restore deleted email messages either on an individual basis, or in batch; let's first show you how to restore a single email from the trash.
First, load your deleted emails by clicking on the "Deleted" link / button on the left:
You will now see a listing of all emails that were deleted, but have not yet been automatically purged by Windows Live Hotmail. The simplest way to restore a single email is just to drag it from the Deleted folder, and drop it above the email folder in which you want to restore it (the Hotmail inbox, in the screenshot below).
That email message has now been moved from the trash back to your inbox!
To undelete several email messages at the same time, just check each of their checkbox to select multiple emails; once you have selected all the messages you want to restore, click on the "Move to" dropdown menu at the top, and choose the destination folder. And if you want to restore all your deleted emails, just select all of them with the "Select all" checkbox, as shown below: (which would show the Deleted folder in your case, not the inbox as is the case here).
Hotmail Tip: note that whenever you delete an email message in Hotmail.com, it will automatically be moved to the Deleted folder. One notable exception consists of spam emails you found in your Junk mail folder: when you delete one of these emails, Hotmail will permanently delete them, and not store them temporarily inside the Deleted email folder - so, delete with care while inside the Junk folder!