When you install Adobe Acrobat, a toolbar is added to Word and Outlook. This toolbar can prevent you from rearranging the toolbars in Outlook (your arrangement won't stick between restarts) and for most people, serves no useful purpose. You have two ways to deal with this:
Modify the setup to remove it
Edit the registry to keep it from loading
Edit the registry so you can toogle the toolbar off and on
Note: This toolbar is only installed by Adobe Acrobat which you purchased. The free Acrobat Reader does not install this toolbar.
To remove it from the computer completely, go to Control Panel, Add/Remove Programs. Find the entry for Adobe Acrobat and choose Change, then select the option to Modify the installation.
Expand 'Create Adobe PDF" and click on the Microsoft Outlook entry then choose "This feature will not be available". If you want to remove the ability to create PDF from all of the programs listed, click on Create Adobe PDF and select this program will not be available to apply the option to each item under it.
Click Next and finish the Add/Remove wizard.
You may need to provide your Acrobat disk or installation media to uninstall it.
This will not affect your ability to print to PDF using the printer driver. This only removes the toolbars from the programs listed.
If you want to disable it, either because you may want to use it sometime or because you don't have the installation media handy, you'll need to edit the registry.
To prevent the Acrobat PDFMaker COM Addin from loading, go to
HKEY_LOCAL_MACHINE\Software\Microsoft\Office\Outlook\Addins\PDFMOutlook.PDFMOutlook
and change the LoadBehavior value from 3 to 2. Restart Outlook. When you use this method, the PDF functions will still be available in Word and the other Office programs. Note that installing Acrobat updates may reset the registry key.
You can remove the add-ins from other programs by editing a similar key, but it's generally better to use Add/Remove programs, because the keys are reset each time an update is installed.
To hide the toolbar button, create the OutlVisible value:
HKEY_CURRENT_USER\Software\Adobe\Acrobat\PDFMaker\7.0\Outlook\EmailToPDF
Value Name: OutlVisible
Value: 0
The original default Value: 0xffffffff