What is the regperf.exe. Is it harmful? If so, how do I remove it? Is it related to atmclk.exe?

Answer 1

This is a component of Zlob Trojan. Zlob Trojan, otherwise known as Zlob.cy, is a Trojan that typically infects computers by being launched when a codec for Windows Media Player is installed. Upon execution, it drops files in the registry, and downloads more malware, including other Trojans that may be used to control the user's system remotely

u must use Prevx1 to remove it
download it from here and use it for removing it

http://aknow.prevx.com/zeroL/InstallPREVX101020052.exe