How to uninstall crystalhd-dkms from Ubuntu

Uninstall crystalhd-dkms

To uninstall just crystalhd-dkms package itself from Ubuntu execute on terminal:

sudo apt-get remove crystalhd-dkms

Uninstall crystalhd-dkms and it's dependent packages

To uninstall the crystalhd-dkms package and any other dependant package which are no longer needed on Ubuntu.

sudo apt-get autoremove crystalhd-dkms

Purging crystalhd-dkms

If you also want to delete configuration and/or data files of crystalhd-dkms from Ubuntu then this will work:

sudo apt-get purge crystalhd-dkms

To delete configuration and/or data files of crystalhd-dkms and it's dependencies from Ubuntu then execute:

sudo apt-get autoremove --purge crystalhd-dkms

crystalhd-dkms package information

name crystalhd-dkms
section kernel

Crystal HD Video Decoder (Linux kernel driver)

website support/ crystal_hd/ 

More information about apt-get remove

Advanced Package Tool, or APT, is a free software user interface that works with core libraries to handle the installation and removal of software on Debian, Ubuntu and other Linux distributions. APT simplifies the process of managing software on Unix-like computer systems by automating the retrieval, configuration and installation of software packages, either from precompiled files or by compiling source code.

apt-get is the command-line tool for handling packages, and may be considered the user's "back-end" to other tools using the APT library.

apt-get remove is identical to install except that packages are removed instead of installed. Note that removing a package leaves its configuration files on the system. If a plus sign is appended to the package name (with no intervening space), the identified package will be installed instead of removed.

See Also

How to install crystalhd-dkms package on Ubuntu