downgrade win 10 enterprise to win 10 pro

My Dell oem win key is win10 enterprise that i can not update 1703.
Can i downgrade win 10 enterprise to win 10 pro?
windows update will release update 1703 for enterprise or not?

Guide to downgrade Windows 10 Enterprise to Professional:
1. Open regedit.exe and navigate to HKLM\Software\Microsoft\Windows NT\CurrentVersion
2. Change ProductName to Windows 10 Professional
3. Change EditionID to Professional
4. Navigate now to HKLM\Software\Wow6432Node\Microsoft\Wind*ows NT\CurrentVersion
5. Change ProductName to Windows 10 Professional
6. Change EditionID to Professional
7. Close regedit.exe (no need to restart)
8. Start the Windows 10 Pro installation from your installation media.

NOTE: A valid product key for Windows 10 Professional is required.

i don't understand when i buy this tablet it include win 8.1 pro. when changed to win 10 it change to enterprise.
now i want it back to win 10 pro i need to buy win 10 pro key.
win 10 enterprise need to have user in volume licensing service center that i have not buy that.
Can i update win 10 enterprise 1703 with out VLSC?

THK for your recommentation but i don't want to download iso every time windows update.
if i can change it back to pro, windows update will do it for me.

may i ask for windows assistant to support win 10 enterprise ?

What does Showkey Plus show for Windows product keys (either installed or in UEFI firmware)?
ShowKeyPlus - Windows 10 Forums

Note: just click on the product keys to blank them out, then you can post the screenshot.

If you have a Windows 8 Pro product key stored in UEFI, then you can just clean install Windows 10 Pro and it will activate itself based on the Windows 8 Pro product key stored in UEFI. Whatever version of Windows 8 product key is in UEFI (If there is one) - that same version of Windows 10 will pick it up and activate itself.

I would try downgrading to Windows 10 Pro using the registry edits provided in post #2, then try to change the product key on the activation page under settings, Updates & Security to the Windows 8 Pro product key stored in UEFI given by Showkey Plus.