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.

Solution:

  1. Re-install SQL Server Express
  2. Install SQL Server Management Studio
  3. Attach back the database file (.mdf)

Please Refer : How to install Microsoft SQL Management Studio

AND
Please Refer : How to manual attach database into SQL Server with SQL Management studio