Q: icloud will not allow me to tick photo stream on my iMac, yet it streams to my mac book from my iphone any help appreciated please????

So as I guessed yhou do not meet the minimum requirements - from the article I linked to (that  you claim to have read)

Open iPhoto ’11 (version 9.2 or later) or Aperture (version 3.2 or later) and click the Photo Stream icon in the left column. Then click Turn On Photo Stream. Shared Photo Streams require iPhoto 9.4, Aperture 3.4, and OS X v 10.8.2 or later.

Had you actually read the links and answered the questions this would have been a single answer thread - you need to purchase iPhoto '11 in the App store if your system supports it and if you actualy have Mt Lion

I find you very rude.

Name calling - not a good way to get  get cooperation for volenteers

LN