Oh and one more thing - did you try killing a monster that gives experience after it disappeared? Maybe it just needs a little poke to pop back up ;)
I think something must have gone wrong in the installation up to Cataclysm, took long enough i can tell you on line, but i have a disc copy of burning crusade, so i will try installing this before i start again.
Many thanks for your reply, i appreciate your help :)
Can you create a Death Knight, Blood Elf, or Dranei?
I dont know really if it matters but I think you have to wright down some codes or buy from battle.net =)
If you haven't already done this, use the account link at the top of the page to access your account. From what I remember, if you are missing a product key on your account, there will be a link on the right of the main account page to add a product key.
On this page, you can also check that under "your game accounts" it says World of Warcraft: Catacylsm. If it says Standard (I think it is), Burning Crusade or Wrath of the Lich King, your account is only upgraded to that level, and you will need to add product key(s) to bring it fully up to date.
It hides everything, your health and mana bars, your XP bar, your mini map, your quest list, the whole works. Maybe he pressed this by mistake?
The WoW experience bar and art on the bottom isn't movable without downloading addons, so the only reason it would be gone is if for some reason you aren't able to advance in the game,
I think it can be removed from the Interface options, or something. Pretty sure I've done it once or twice, or at least with Pet XP before it was removed.