Thank you so much friends , i bought Samsung PM961 and it's working pretty well with my board , detected in BIOS , no issues with installing windows , giving me good read and write speeds.
The only problem i faced is that in order to install new windows i had to remove my hard drivers except NVMe other wise it was giving me an error "Couldn't install windows on this location" and also make sure when allocating space to your ssd in disk management options select "MBR" disk type not "GPT" , system will not install windows in "GTP" mode , and also remove all hard drives to install window on NVMe SSD.
That isn't an "error" as such. SATA drives always have preference over NVMe drives. If you look in task manager, your SATA drives are listed first, NVMe drive last (disk0, disk1 and so forth).
Booting wise, MBR always takes precedence over GPT under Windows. What has happened was booting Windows in MBR mode, then trying to install on a GPT formatted drive. That wont work, because Windows will try and write an MBR boot record to the GPT drive. Same thing the other way round, Windows trying to write a GPT bootloader on an MBR drive.
diskpart > clean is your friend here. But should be used sparingly, since it'll nuke ("clean" really is an appropriate name for that command) the drive selected, with no way of recovery.
You might have noticed in the UEFI boot menu, that the drive (ODD or USB) used to boot is listed twice, one of which is listed something like "UEFI:", selecting that is the way to install on a GPT drive.
I hope that makes sense, some things are just easier to show then describe. Since you got Windows installed, no reason to worry about it. If it was a laptop, I'd do a reinstall, since power saving on such are highly dependant on UEFI mode.