REGEDIT4

[HKEY_CLASSES_ROOT\msnim]
@="URL:msnim Protocol"
"URL Protocol"=""

[HKEY_CLASSES_ROOT\msnim\shell]

[HKEY_CLASSES_ROOT\msnim\shell\open]

[HKEY_CLASSES_ROOT\msnim\shell\open\command]
@="\"C:\\Program Files\\MSN Messenger\\msnmsgr.exe\" \"%1\""
@="\"C:\\Program Files\\Windows Live\\Messenger\\msnmsgr.exe\" \"%1\""