How is God's name spelled?

The correct spelling of God's name according to the KJV Bible is YHVH, which is Englished as Jehovah.

The Strong's Concordance has: #3068, Yehovah (yeh-ho-vaw). This is the englished spelling and the phoenetic spelling.

There are several acrostics in the KJV Bible that shows the spelling as YHVH. One of the acrostics is found in Psalm 96:11 - The initials of the 4 Hebrew words of this verse spell His name YHVH.
The book of Esther has this acrostic 4 times, twice forward (YHVH) and twice backward (HVHY).

Esther 1:20 (backward - HVHY)
Hi Vekal Hannashim Yittenu

Esther 5:4 (forward - YHVH)
Yabo Hammelek VeHaman Hayyom

Esther 5:13 (backward - HVHY)
zeH eynennV shoveH leY

Esther 7:7 (forward - YHVH)
kY kalethaH elayV haraaH

(For those with a Companion Bible see appendix 60 for a much deeper study on the acrostics.)

These acrostics alone should be pretty convincing that God's name is spelled YHVH (not YHWH). This is why the name Jehovah is used in the Bible, with a V not a W.

Jehovah, as used in the Bible is God in covenant relation to those He created. The name Jehovah means the eternal, the immutable one, He who was, and Is, and Is to come.

The name Jehovah is found only 7 times in the KJV Bible:
Exodus 6:3, Psalm 83:18, Isaiah 12:2, Isaiah 26:4,
with Jireh Genesis 22:14,
with Nissi Exodus 17:15,
with Shalom Judges 6:24

There are 134 verses where Jehovah was changed to Adonai in the original text. Out of extreme (but mistaken) reverence for the Ineffable Name "Jehovah", the ancient custodians of the Sacred Text substituted in many places "Adonai". In the KJV these changes are written as Lord.