Whether you like it or not, wipe all and reinstall is what you need to do.
+1 And some very specialised rootkit can even infect the BIOS so in a company environment you need to flash the BIOS before reinstall. You can't trust a computer that have ever been infected.
http://www.tomshardware.com/news/bios-virus-rootkit-security-backdoor,7400.html