Serial Port Not Working

Code 10 is almost always a driver issue.
Is your board a REAL arduino or a cheap clone ?
If it is a clone you probably require drivers that are not part of the Arduino package.
CH340/341 or CP2102.
Usually best to install those as Administrator but not always necessary.

COM 3 would be the first port over the usually reserved COM 1 & 2 that windows hold back.