I have changed permalinks from default to numerical
1. Which version of WP/MU are you running? -3.1.2
2. Did you install WP/MU as a directory or subdomain install?–I installed on wamp as a directory
3. If a directory install, is it in root or in a subdirectory? — it is in localhost/wordpress/
4. Did you upgrade from a previous version of WP/MU? If so, from which version? -NO
5. Was WP/MU functioning properly before installing/upgrading BuddyPress (BP)? e.g. permalinks, creating a new post, commenting. –yes
6. Which version of BP are you running? —1.2.8
7. Did you upgraded from a previous version of BP? If so, from which version? -NO
8. Do you have any plugins other than BuddyPress installed and activated? If so, which ones? -No
9. Are you using the standard BuddyPress themes or customized themes? – bp-default
10. Have you modified the core files in any way? – NO
11. Do you have any custom functions in bp-custom.php? -NO
12. If running bbPress, which version? Or did your BuddyPress install come with a copy of bbPress built-in? -NO
13. Please provide a list of any errors in your server’s log files. –
14. Which company provides your hosting? -WAMP
15. Is your server running Windows, or if Linux; Apache, nginx or something else? -Apache
In other words, mod_rewrite must be enabled in your server for “pretty permalinks” which is required by BuddyPress to work.
https://codex.buddypress.org/getting-started/before-installing/#system-server