I've installed windows 10 with bios set to legacy, windows hangs on shut down?

I've installed Windows 10 on my new Lenovo G50-70 with Bios set to legacy boot, At first i didn't know how to enter to the bios so i pressed alt+f12 to choose which device to boot from so i found 4 options where there efi+HDD so i used that option to install windows 10 with GPT partitions. after that Windows 10 start to get slow and refuse to shut-down, and now after i figured out how to enter to the bios i changed the boot to UEFI.

My question is what i've done did correct the mistake that i did or i should to reinstall Windows 10?