How do I get to icon names to show on start toolbar

Is it happening with every theme or just the one theme?  If it is just the one you need to contact the themes author as evidently he/she has the text content margins set incorrectly.  But then again it might have been intentional, the way he/she wanted it to be.

everytheme even if i change back to default Windows XP original theme

You might try doing a System Restore to a time before the problem occurred, if that does not work it sounds like you will be needing a repair or reinstall of Windows XP.