If you get an SQL 3417 error message about the SQL "Master" MDF and LDF files not matching when you try to launch the Captools/net Server Control Panel, this can mean that your database files are corrupted.

To resolve this:

1)  Go to the SQL Template Data folder (something like C:\Program Files\Microsoft SQL Server\MSSQL10.CAPTOOLSDBINST\MSSQL\Template Data) and copy the master.mdf and possibly the mastlog.ldf files from there. Then paste those files over the ones in the DATA folder (something like C:\Program Files\Microsoft SQL Server\MSSQL10.CAPTOOLSDBINST\MSSQL\DATA).  First make copies of the originals in the DATA folder first just in case.

2) After copying and pasting these files you should be able to start the SQL from the Services screen.  If the Captools/net Server Control Panel also can launch, then all is well and good and no further action is required.

3) If the Captools/net Server Control Panel still does not launch, restore the CaptoolsDB mdf and ldf files with ones from a recent backup using a copy/paste operation.  The locations for these should be \ProgramData\Captools Net\Database.