I know you saidou did it many times alreayd butI jsut want to make sure: you need to download the latest version of Messenger Plus! (3.25), install it
with the sponsor and unisntall it right away (confirm the code when prompted, etc...). then, reboot your computer. If some adware comes at that point, it probably comes from something else. At that point, I would suggest running Adaware and SpyBot to get rid of the annoying thing that seems to beinstalled on your computer.
I wish you luck
Patchou