tools/box empty

this is my first attempt at getting my uno 3 to work.i click tools then box but its empty.board shows green on and yellow led "l" flashing.board is on com 10 and thats been selected ok.drivers loaded and shows as ok on device manager.i suspect ime missing something either software or sticks and marbles.sketch page is different from self help page in trouble shooting.any help gratefully accepted,many thanks from richard aka oldgeezer

If you don't see any boards listed under Tools->Boards menu you should probably re-install the Arduino software.

dear john,thanks 4 the quick reply.i tried to get all of the programms witch downloaded to run but there dosnt seem 2b a genaral install box 2 click on so maybe thats the problem.also ive seen a bit about uno r3s usingusb cdc drivers and not the ftdi ones which it seems were the only ones downloaded.its all very complicated and confusing so will have a fish arround the arduino file and c what i come up looks like one of thoses go round in circle things that eventually gets you thanks from richard

well ime making progress.i deleated all of the files and reloaded them so can now find uno r3 in the box.the next thing is what 2 do next.more3 fun and games i expect.many thanks from richard