where do i find gdmsetup

To get best help tell us what release of Ubuntu are you using...?

Thank you.

Hello,
Another alternative way to install themes:
How to set up a new theme for GDM:

First make sure to have the universe repositories [https://help.ubuntu.com/community/Repositories] enabled,
Then,

sudo apt-get install gdm-themes

Now run

sudo gdmsetup

When gdmsetup opens, you see a list of themes you can select from.
Select your preferred theme and close gdmsetup, done.

This step is not needed if you have downloaded a theme from art.gnome.org and wish to add it.
Then you select, after opening gdmsetup, add, then select the package you downloaded, click install and gdmsetup will install the newly downloaded theme for you. (Dont extract the downloaded package yourself!)
Of course this also goes for all other distros that use gdm exept for the “sudo apt-get install gdm-themes” bit.

hope it helps,

br,

Bhavani Shankar.

It's under System->Administration->Login Window

Gdm themes are located in /usr/share/gdm/themes
To set the default theme manually, edit the file /etc/gdm/gdm.conf-custom