Both AVG and Malwarebytes scanner cannot find anything
do you have AVG and avast installed ?

having multiple AV installed can/will create all kind of windows errors and false positive detections…

Never install two antivirus (see reply from quietman7)
http://www.bleepingcomputer.com/forums/index.php?s=7c8217673a726b92cfc91ecfd4294a29&showtopic=260844&view=findpost&p=1441638