Lately, it happens very often to been asked to check some IE behavior: command “open in a new tab” is not available.
Only “open in a new window” command is available.
No reinstall is needed, no tricky registry update or other hacker actions. 
IE7 and IE8 have a tab configuration window, you may find it in TOOLS\INTERNET OPTIONS menu’.
You may enable and disable tabs via this menu’.
A couple of screenshots I hope will be helpfull.
Technorati tags: Internet Explorer, Tab
