It is not from any RAID and works perfect with windows.
I followed and ran chkdsk /f, connected to my notebook with windows 7 with usb-adapter. No errors found.
Frankly I'm not sure how "reboot into windows twice" part was completed, because it's not a bootable drive and it seems that usb-adapter has some issues too (it got no poweroff button, so I just have to unplug the power cable after disabling in windows and unplugging usb. At this moment it is still spinning, so it causes "power lost" error in SMART every time), but that never affected anything as far as I can tell.