SQL Server 2005 error while starting service
It looks like your [model] database has become corrupted in some or another way, in particular, SQL is reporting that the log scan failed.  

If you had a customised model database, you should probably have a backup of it too.  

You would need your installation media to recreate the system databases, and thereafter (if you have one) restore the latest backup of your [model] database.  

You can achieve this by running the following command line :

start /wait &lt;CD or DVD Drive&gt;\setup.exe /qn INSTANCENAME=&lt;Instance&gt; REINSTALL=SQL_Engine REBUILDDATABASE=1 SAPWD=&lt;NewStrongPassword&gt;

This will set you up with an instance without your user databases and all default settings.  You can then proceed with the restore of your [master], [msdb], and [model], and also the rest of your databases.