You may refer the following link and try running the Malicious Software Removal Tool to remove the malware from the system.
Also refer the link (which applies to Windows XP also):
Hope this information is helpful.
Microsoft Answers Support Engineer
Visit our Microsoft Answers Feedback Forum and let us know what you think.
If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.