Dear Harsha,

Hope you are doing well

1) Go to the windows machine that hosts the Oracle database server
2) Go to Start -> Run -> Services.msc in windows. Locate OracleService (here OracleServiceORCL) and click on "Start" to start the oracle database service (if not already running)

3) Once it is up and running, from the command prompt run the following:

    tnsping < tnsalias >

(tnsalias entry you can find it in tnsnames.ora file)

Please let me know if you have any further issue regarding this.

Feel free to contact us in case you have any query.