If you are encountering error 80004005 when signing in, please try the following:
I. Verify if you have the latest version of Windows Live Messenger by clicking on Help-->About Messenger and reading the Build number. You should see Build 8.0.0792.00
II. If you see any other number listed there, install the latest version of Messenger from
http://get.live.com/messenger/overview .
III. Attempt to sign into Messenger again.
If you are still unable to sign in:
IV. Change Windows Explorer settings
a. Right click on the Start button and choose Explore from the short-cut menu to
open the Windows Explorer window.
b. In the Windows Explorer window , click on the Tools menu followed by Folder Options. Click on the View tab. In the Advanced settings list, checkShow hidden files and folders and uncheck the option Hide extensions for known file types under Hidden files and folders. Click on OK to close the Folder Options window.
c. In the Windows Explorer window, click on the View menu followed by Explorer bar and ensure that the Folders option is checked. This will ensure that you are able to see the folder list on the left side of the Windows Explorer window.
V. Delete the Contacts Cache folder by following the steps below:
a. Right click on the Start button, choose Explore from the short-cut menu to open the Windows Explorer window.
b. In the Windows Explorer window, goto the Folder list on the left pane and navigate to the folder C:\Documents and Settings\<Your Windows logon name>\Contacts\<Your Messenger email address> where <Windows Logon name> is the login name you use to sign into windows and <Your Messenger email address> is the address that you use to sign into Messenger
c. Delete all the files that are within the <Your Messenger email address> folder.
d. Right click on the Start button, choose Explore from the short-cut menuto open the Windows Explorer window.
e. In the Windows Explorer window, goto the Folder list on the left pane and navigate to the folder C:\Documents and Settings\<Your Windows logon name>\Local Settings\Application Data\Microsoft\Windows Live Contacts\<Your Messenger email address> where <Windows Logon name> is the login name you use to sign into windows and <Your Messenger email address> is the address that you use to sign into Messenger.
f. Delete the real and the shadow folders that are within the <Your Messenger email address> folder.
VI. Sign into Messenger again.
VII. If the problem persists please contact Windows Live Messenger support at
http://support.live.com.