If you are using Windows Live OneCare and you have been infected, but OneCare did not detect or cannot remove the malware, please contact support to report this and for help with removal.
How to reach support (FAQ) - http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90
If you are in North America, you can call 866-727-2338 for help with virus and spyware infections. See http://www.microsoft.com/protect/support/default.mspx for details. For international information, see your local subsidiary Support site.
To answer your specific question, if your PC is already infected, installing OneCare will not likely remove this infection. There are many variants of this malware and many are very difficult to remove using most of the available solutions, including OneCare. I suggest either contacting the Microsoft antimalware support team or go to www.bleepingcomputer.com and search for this infection for details on how to remove it yourself.
-steve
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator