Computer is acting strange. Please help!

It seems to be running fine now but I'd like to know wtf happened and if it should be something to worry about. It seems to be something with my motherboard and it's usb ports. I will start out by saying that I have an usb mouse and whenever I start or reset my machine it doesn't work. No lights on it or anything. I have to unplug it from the usb and plug it back in to have it work. SOMETIMES it happens with my keyboard as well. (No matter what usb they are plugged into) Once I do that it is fine until the computer has to restart again. That is why I usually put it to sleep instead of shutting down.

Anyways after finally playing the awesome DayZ mod I exited game and put my computer to sleep at 3:00am. I woke up today and came into the office where I found my computer on. fans on. monitors blank and the lights orange (on the monitors) instead of blue. I said ok and turned off my computer. I waited a few seconds to turn it back on. I hit the button and all the fans turn on but the monitors are blank still. It doesn't post. It doesn't do anything. I repeat the process a few times. Nothing. I go to unplug my computer's power source and all the usb ports and plug them back in. Pressed the button and it finally posts but I get this message "Warning! CPU has changed. Please re-enter cpu setting in cmos setup and remember to save"

I hit del on my keyboard and it doesn't do anything. Well, this is one of those times that my keyboard doesn't work so I have to unplug it and plug it back in. it works. I go in bios and just go to save and quit. It fixes and goes to the starting windows screen. After that the screen goes blank again and the lights on my monitors turn orange. I was getting ready to press reset again but I hear a click and the image starts to glow on the screen. It is exactly how I left it when I put it to sleep. The same webpages, everything! For one.. I unplugged my computer. How is that even possible? I am confused at that. My computer starts going slow as hell though. I reset it and it starts up like nothing happened.

What is going on? Why did it do that? What can I do to prevent that from happening again? Do I need a new motherboard? Is my CPU still over clocked? (I don't understand the OC stuff but I managed to get mine)