Unlike Windows XP, the common tasks pane is shown at bottom in Windows Vista and Windows 7 explorer and is called "Details Pane".
Sometimes you might find that the Details Pane is no longer shown in Explorer window. I have received many e-mails asking for its solution, so here I'm posting a detailed tutorial with screenshots to re-enable missing Details Pane in Vista and 7 explorer:
Without Details pane the explorer window looks like as following:

Click on "Organize -> Layout -> Details Pane".

It'll re-enable the Details Pane:

Sometimes you might face a strange problem when the option to re-enable "Details Pane" in "Layout" menu will be missing:

Don't worry. It happens when Classic folder option is enabled in "Folder Options". Go to "Organize -> Folder and Search Options" and enable "Show preview and filters" option.

Apply it and it'll re-enable the option to show/hide Details Pane and Preview Pane.
NOTE: If you are wondering why the Details Pane is shown at top instead of bottom in the screenshots, then you can visit following tutorial:
How to Move / Show Details Pane At Top in Windows Vista Explorer?
Posted by: Vishal Gupta | Categories: Troubleshooting, Windows 7, Windows Vista
rk
hi,
I am using win 7 professional sp1. followed all above steps but still can's see deetails pane. organize layout - > details pane is not available. gpedit changes are also done as suggested.
Jessica
My Details pane mysteriously dissapeared a few days ago and I was going crazy trying to figure out how to get it back. With the help of your tutorial I now have it back. Thanks so much! :)
VG
^^ Glad to help you. :)
MA
Thanks so much!!
krish
thanksss man
nagisa
thank you! you've helped me! ^^
starwatcher
thanks mate... have been irritated for a while without d details pane... finally got it back
Moomi
Thank you so much!! Spot on!
Pete121
Thank You. Great Work. Very much appreciated. You'd think all these little but annoying problems would be solved by the Windows Vista itself, but you'd be wrong. This is just one example of a myriad of minor pains that have no resolution in Vista itself. Its a damn shame. Thanks to individuals like yourself users can overcome these damned inconveniences. Again Thanks Very Much!!