OracleSetviceSID stops itself

I hav开发者_StackOverflowe oracle 10.2.0.4 version..Some days before everything was well..but after changing tnsnames.ora file(I had just one SID of database,which is located on my computer.Then I have added SIDs of other databases which are located on another servers) OracleServiceSID stops itself after a while and user is automatically disconnected...How to solve this problem?I want OracleServiceSID to remain started...

After searching on the internet I found the following:

Start->All Programs->Oracle..->Configuration and Migration Tools->Administration Assistant for Windows

Collapse the following folders:
 Oracle Managed Objects->Computers->Comp_name->Databases->SID<-right click->Start Service

File->Save

And after that everything works fine...Maybe It is a solution or temporary solution..Not sure..

You should need to investigate why this issue occurred to prevent this issue in future too. Check event viewer for further investigation of issue.