Raspberry Pi 3 B+ Error 0x8007000d

[Sentinelace]

I am having no luck. I have an samsung EVO 32gb card that is on the approved list of SD cards. I tried flashing the preview core which is under a pi2 folder on my c drive. I get this error and doesn't even attempt to flash. Is the pi 3 not supported yet?

[lpsw]

It's not clear from your description, but assuming the 0x800700d is being thrown by Windows, it usually indicates the Windows file system has been corrupted - nothing to do with your Pi.
What are you using to flash the SD card?.