I've got an M-78. Running W8 Pro with Media Center, 1TB Seagate HDD, 16GB RAM, 3 External HDDs branded Toshiba 3T, WD-3T, Seagate 3T all plugged into individual 3.0 USB ports. BIOS is set to Optimized defaults. Also I had a USB 2.0 USB Seagate 500MB External plugged in though not the usual.

Main issue; unstable lengthy boot (I know the BIOS is looking for Operating Systems) and the best way to boot is with USB's unplugged.

This PC has been on, with High Performance Power, for a couple days without being used. This morning I hit the spacebar on the keyboard and nothing. The power button had a light. It acted like it was hibernating. I pressed the power button in until the fan started up and attempted to boot. The LENOVO start screen came on and sat there. I went into the BIOS and there was the 500MB Seagate recognized but the other SATA 1 was Unknown Unknown. I hit F9 to reset to Optimized defaults and rebooted. No operating system. I then pulled the power cable and removed all the USB drives. Hit the power button and rebooted fast & fine.

I have had odd problems like this since getting this machine. I don't know if it's the machine or the USB or BIOS or motherboard. Everything is new. This originally came with W7 Pro but came with Windows 8 Recovery DVDs which I used to set up the factory defaults for W8. Since then I have removed some bloat ware, (mostly Lenovo Power Management) and Added W8 Pro.

Knowing that this is all kind of open ended, I just wanted to put this out in case anyone else had issues similar and if there is a fix.