On a slightly related matter, I had an issue with my Lenovo G500 with Win10 last weekend - it refused to boot beyond the splash screen for over an hour or more; removed battery and power lead for five mins, no go.
Used older laptop to search for solution/inspiration, apparently Lenovo can be prone to this problem; remove power sources and back, then briefly unplug CMOS battery - worked a treat!
Must make a bootable DVD, though I'm not sure it would have helped in this instance...