Windows 8.1 partition problem

I burn windows 8.1 with rufus for Uefi boot system then started the installation . at the partition dialog I deleted old Windows partition and click for new one but I got this error message . Kindly help me.

and this

What is hidden under the Windows Setup error message? Looks like there is unallocated space (good) and something else, What is it? Have you tried deleting that also so you have only unallocated space, then simply click the Next button, do not setup anything, let the installer setup what it needs.

solved by deleting all. Thanks

I want to know if I have a laptop with both MBR and GPT (legacy and Uefi) systems and my laptop harddisk is formatted in MBR type then can I insatll the windows 8 using legacy mode without booting into uefi mod and formatting again the harddisk into GPT?

Yes, Windows 8 and 10 will install to a MBR disk.

In MBR (legacy) mode windows will detect the OEM key automatically ?

I have no personal experience of it but yes, everything I've read says it will.