- Mixed mode

- Trying to log in with a different account than I installed with. Logging in with my network account, which is defined as sysadmin in sql server.

- Not sure what you mean. I configured everything via the install program, then used SQL Configuration manager later to add a trace flag (3226) and restarted the service for it to take effect.

- Browser service is running.

Based on your question, I tried connecting using the same account I installed it with and got the same error.