BuddyPress is a plugin that requires WordPress. It does not, nor cannot, have its own install.
Your issue is more than likely caused by your theme. It is not updated to work with BuddyPress. You need to deactivate BuddyPress. Since you cannot gain access to the admin backend, you need to drag the buddypress folder out of your /wp-content/plugins/ folder. Try logging in again. It should now be possible. Reinstall BuddyPress but do not activate until you have gone through the below process.
Here is some information on converting your WP theme to work with BuddyPress.
By the way, if you are using an older version of WP (2.9.1 or 2.9.2) you will have to click the “Activate BuddyPress Site Wide” link instead of the regular “Activate” link.
I am using 3.0. I installed the conversion plugin, and I am at Step Three
Now that the template files are in the correct location, click through your site (you can come back to this page at any point). You should see a BuddyPress admin bar at the top of the page, try visiting some of the links in the “My Account” menu. You should find that BuddyPress pages now work and are displayed.
No such admin bar appears anywhere on my blog. Tried installing buddypress again and reactivating after following steps, and no go, blank page, must ftp delete.
Tried in specific order you suggested. No go.
I figured it out. I needed to disable all my plugins and install a compatible theme. The theme updater did not work. Boy, this must be really new if most themes are not compatible.
Parts of themes have to be written specifically for BuddyPress; the project itself has been out for at least 18 months.
I really did not wanna create a new thread as my problem is very similar to this current thread.
The only issue I can’t wrap my head around is all I have is a plain vanilla WP 3.0 install. I got to the plugin page, searched for BuddyPress and installed it. All’s well till this point. The moment I activate the BP plugin, I lose the control panel. The default theme for WP 3.0 is the 2010 theme. Is there something else I’m missing?
For now, I moved the BP plugin outta the plugin dir; so got the control panel back. Any hints/thought?