Well I am sorry if you did, but my PC was hijacked by Spy Sherrif for a few days. Eventually, and with the help of Hijack This http://hijack-this.net/ I was able to remove the offending program.
How did I know my PC was infected?
1. Phony indicator on tool bar saying I was infected and should install Spy Sherrif
2. Replacement home page saying I was infected and should install Spy Sherrif
3. My PC was busy from time to time, doing what, I did not know, until I got a thousand or so returned email from my AVG antivirus with message like:
This is the AVG E-mail Scanner program.
I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.
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Cannot open smtp connection to '205.123.123.12'
Connect: A socket operation was attempted to an unreachable host. (10065)