Freeze randomly without BSOD.

Hello, i have already had issues before with this brand new machine, mainly BSOD's which i solved by replacing usb drivers from 32 to 64bit corresponding to my win7 version, i use this pc mainly as a DAW for music production (fruity loops/ableton live), besides usb mouse/keyboard (microsoft standard) i only have virus ti 2 synth connected through usb and using it as both midi keyboard and soundcard, lately im experiencing freezes with do NOT result in a bsod later on, i just have to physically restart or shutdown. couldnt find anything on the event viewer or any other acceptable way of finding issues, attached the SF diag collected files.

that fireface is no longer connected. i got rid of this device few weeks ago is is possible you were looking at older logs? also since posting this thread i got a blue screen!! i attach newer SF diag collection! please focus on everything suspicous from the last 48 hours, im really very upset since this is a new machine and serves me for most of the day. thanks alot!

ran sfc scan 3 times as you suggested all came good, ran a full scan with microsoft security essentials all clear also.
i also want to mention that i also had before a period during which i had 3 bsods a day pointing to the intel extensible host controller driver or to the virususb.sys driver, solved this buy manipulating the usb3 controller driver setup to install the 64bit version and not the 32 one which was installed automatically for some reason, that solved the issue for a while until now, what else is there to do ?

i think i got onto something, at first i thought it was a coincidence that on two freezing occourences the same second i heard my air conditioner sounding a single click as an indication for whatever.. i messed with the electric plugs and the moment i disconnected and reconnected the air conditioner back my pc froze again,just raising a thought that non grounded sockets might be the issue, my computer is connected to a grounded wall socket so it might not be the one affected directly by the AC, but both my virus ti and the AC are not grounded so perhaps the AC affects the synth and it somehow affects the pc via the usb connection resulting in a freeze, is such a thing possible?