Originally posted by Turias:
like OS version... computer type...
Those, and also provide all other information you can.
Which version of iTunes have you been using?
What did you do before iTunes vanished?
If you search for iTunes in the Finder, can you find it somewhere?
Where did you download the new iTunes installer? URL?
Which volume did you select to install iTunes to?
Is it the boot volume?
How much free space does it have?
What's the exact error message the installer gives you?
Can you post a screenshot of the Installer at the point where you stuck?
etc. pp.