Try repairing Windows Live Messenger as well. (Add/Remove Programs>Windows Live Messenger>Click here for support info>Repair)
Then install Messenger Plus!, if it still doesn't work, do steps
- Open Windows' Control Panel (Start > Control Panel).
- Select "Add/Remove Programs" (Windows XP) or "Programs and Features" (Windows Vista).
- In the list of programs, double click on "Messenger Plus! Live".
- Choose "Repair Messenger", leave the first 2 options checked and click Next.
- Once the reparation is complete, restart Messenger. Your software will now be running with no scripts or skins running.
If your problem still persists I can't help anymore
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