Malware from YTD Downloader! HELP!

In a rush, I stupidly downloaded YTD Downloader... Then i read the reviews... http://download.cnet.com/YTD-Video-Downloader/3000-2071_4-10647340.html

It has affected all sorts on my computer, chrome, safari, Internet speed, screen settings.

I need to help to remove all the Malware from my computer and brink it back to the way it was running last week.

A step by step guide would be greatly appreciated...