Here's some information I found about 'Winfixer' and how to remove it.
Found this info on the following site:
http://www.symantec.com/avcenter/ven.../winfixer.html
Behavior
WinFixer is a Security Risk that may give exaggerated reports of threats on the computer. The program then prompts the user to purchase a registered version of the software in order to remove the reported threats.
Symptoms
Your Symantec program detects WinFixer.
Transmission
This security risk is manually downloaded and installed.
Hope this helps. I suggest you run a full scan of your pc and also update your anti virus software.