Changing the default theme
Posted by andrea in Let’s face it, the default theme is ugly. Sure it was cool way back when, but now everyone has rounded corners and big blue headers. There may come a time when you would like to have the default theme on signup be something else.
For this, I am going to assume you’ve already picked another theme you like and tested it to make sure it works and behaves liek expected. Surf on in to your server, however you like. Find the default theme folder in wp-content/themes/. Tip: it’s called “default”. 
Rename the folder to something like default-old.
Now, find your new theme folder with the theme you like. Rename that folder to “default” (no quotes).
Seriously, that’s it. Withoin the code itself, it is only the folder name that is used in the case of new blog setup and to have a theme to revert to should a previously selected theme be removed.
If you want, you can disable Kubrick (the original default theme) so users cannot select it, by going to Site Admin -> Themes and click the “NO” radio button. Don’t forget to save your changes.
I’d also like to remind you to note that you made this change in your own personal changelog file. This helps by keeping track of any changes you made so you can repeat them in case of an upgrade, a re-install or some tragic unforseen event.
Hey, it can happen 
and it’s a good habit to get into.
Like most things “WP”, I didn’t know it was that easy.
[...] Changing the default theme is yet another hack that takes you through changing the default theme for WPMu. [...]
It’s a good tip! But i’m trying to create my own theme, and to add some functions. It’s a good training !
And trying to have bbpress working too with the same theme is “la cerise sur le gateau” like we say in french
thanks, it’s simple light, speed, and cool !
Nice! I love it - one more question -
How can I have a theme enabled for my blog (the main blog), but not allow users to see it when they can select their themes? I don’t want them to have my theme…
You have to change the settings in the site admin settings. There is an option on the right hand side that allows you to make it in the available themes for the users.
I don’t see why we should even bother renaming the new theme to default.
[...] WPMU Tutorials » Changing the default theme (tags: WordpresMU Themes) [...]