Try deleting these temporary files, especially the Contacts ones.
Note: You will have to go to Tools > Folder Options > Show hidden files and folders .. to view some of the files.
If the folder doesn't exist, even after showing hidden files and folders, move onto the next one.
Depending on which version of Windows you're using, delete the following..
quote:
Originally posted by CookieRevised
For example, in XP:
C:\Documents and Settings\your_username\Application Data\Microsoft\MSN Messenger\
C:\Documents and Settings\your_username\Application Data\Microsoft\Windows Live Call\
C:\Documents and Settings\your_username\Application Data\Microsoft\Windows Messenger\
C:\Documents and Settings\your_username\Local Settings\Application Data\Microsoft\Windows Live Contacts\
[...]
C:\Documents and Settings\your_username\Contacts\
C:\Windows\Temp\MessengerCache\
For example, in Vista:
C:\Users\your_username\AppData\Roaming\Microsoft\MSN Messenger\
C:\Users\your_username\AppData\Roaming\Microsoft\Windows Live Call\
C:\Users\your_username\AppData\Roaming\Microsoft\Windows Messenger\
C:\Users\your_username\AppData\Local\Microsoft\Windows Live Contacts\
[...]
C:\Users\your_username\AppData\Local\Temp\MessengerCache\
C:\Users\your_username\Contacts\
Source:
Windows Live Messenger BIG PROBLEM!
Obviously replace your_username with your Windows username 
[...] = Where I've not included a folder as I don't think it needs to be deleted in your case.
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