Arduino and Computer are not in sync

I get the following message when I run the initial Hello sketch.

avrdude: stk500_getsync () : not in sync: reap=0x00

I try both Com1 and Com 3, but neither works.

What must I do?

Give us more details… And have you looked around? It’s the most posted question out here…

So, real deal or China Clone?
Did you install the drivers? If yes, which?
Under Device Manager, is there a ! ?