ComboFix (which is sometimes updated several times a day) and Malwarebytes.

ComboFix will run in safe mode (some infections disable safe mode and running executables which makes things a bit more tricky) so that's were I usually start. After that I'll reboot in standard mode and run Malwarebytes. That usually does the job, though I usually run ComboFix again in standard mode just to be sure.

ComboFix is good at detecting root kits, which are now often installed to keep you from being able to remove the infection. ComboFix will bleep about it, jimmy the root kit, restart the machine and go about its work.

One thing about ComboFix, you have to get it from their site or from Bleeping Computer. It is much feared by malware writers so they have seeded the Internet with fake versions.