Here's my side of story on solving this problem.
I'm using SQL Server 2008 Express Edition on Windows 7
Started SQL Server (SQLEXPRESS) and got error code 3414
After checking on error log, it was showing
The log scan number (19:136:1) passed to log scan in database 'model' is not valid. This error may indicate data corruption or that the log file (.ldf) does not match the data file (.mdf). If this error occurred during replication, re-create the publication. Otherwise, restore from backup if the problem results in a failure during startup.
But i do not has backup of model or any database present in the "DATA" folder. There's a really simple solution for this.
Go to "Binn" directory of you MS SQL SERVER.
For me its "C:\Program Files\Microsoft SQL. Server\MSSQL10.SQLEXPRESS\MSSQL\Binn".
In Binn directory, go to the "Templates" folder.
And there is the model, master and msdbdata database mdf and ldf files which was installed with the MS SQL SERVER.
Replace the database file with the corrupted one.
This works for me.
Hope it works for you because it gets 2 hours for me to solve this problem:crazy: