Trying to block website....help!

Recently, I installed the free Open Office on my laptop.  But, it attached a site called Start.Search.us.com as my home page.  I have tried to uninstall it, but can't find it to uninstall.  I use Firefox and went to tools and reset my home page to Yahoo.....it worked twice and reverted back to the Start.Search....then I went into the tools and blocked Start.search.....it worked twice and was back on the third time.

 

I am trying to see if there is a way for me to manually block it using my Norton firewall....but I don't know how.  Any suggestions?

 

Thanks in advance!