Ok let me start by saying this fixed my computer and I hope it will fix yours. There seems to be a trogan program that redirects searches ie for example... I type in the word Tabasco in the Google search engin and it take me to a page of links that should take me to web pages that have information about Tabasco. However with this trojan installed on your computer it assigns the links to btcar.com a porn search engin. You might say to your self Hummmm I have never visited any of those porno naked people sites. Well my friend mabey you didn't but someone using your computer did. So with out further adue I present to you a way to repent of your sins and wash your computer clean. I used a program called Trojan Remover donload for here http://www.simplysup.com/tremover/download.html
I ran the program and it took 3 trys but after to hard shutdowns and soft reboot my computer is sin free now and google is back to normal. So how did you get this trojan visit here http://forums.spywareinfo.com/index.php?showtopic=60955
for some insite but mostly it was probably you human desire to look at othere humans.
God Bless I hope this fixes you up before trouble comes knocking.