What is your operating system?
You have both Acrobat X and XI installed at the same time?
[topic moved from Adobe Reader to Acrobat forum]
Yes the Acrobat XI was downloaded as a trial.
It’s not recommended to install two version of Acrobat on same machine.
You can uninstall Acrobat XI using following steps:
Click on Start button -> Control Panel -> Programs and Features
Select Acrobat XI form the list and then uninstall it.