I have a clean build of SBS2003 that I did, and after the initial build,
Sharepoint and the companyweb were working ok. However, after I put
Sharepoint SP2 on the system, I’m getting a 403 Forbidden error.

Sharepoint and Sharepoint Admin both give that message.

Backup, Monitoring, WSUS, RWW, and Outlook Web access all work just fine.

Things I’ve tried:

Re-running the Connect to the Internet Wizard

Checking to make sure companyweb did not get switched to ASP.net 2.0 (it’s
still on 1.1)

Checking permissions.

Everything else seems ok. Last time this happened to me, I reformatted the
box and started over, but I’m trying to understand why this is happening in
case it happens on a live server and I can’t just start over.

Any ideas?