Cannot Load OCI.DLL : While Connecting

Sometimes the error "cannot load OCI.DLL" occur whenever we try to connect with the oracle database by using the third-party tools(i.e, toad,sqltools and others) or command prompt . This error may occur because of the following reason .

1.) The oci.dll error may occur because you have not set the correct ORACLE_HOME and path in environment variables . 

2.) It might be possible that the oci.dll file may be corrupt or may not exist on the correct path .

3.) May be possible that oci.dll may not be correct version. (e.g. 32bit s/w will load a 32bit DDL - we cannot for example use a 64bit DLL for a 32bit executable) . 

To solve this issue , consider the below points .

1.) Check the ORACLE_HOME and Path setting in the envirnoment variable.
2.) Check the correct location of the oci.dll path . The path of the oci.dll file is $ORACLE_HOME\bin\oci.dll
3.) Check the oci.dll correct version .

In my case , i am facing this issue because the $ORACLE_HOME is not correctly set in the environment variables . So setting the correct path in environment variables, we find not any error while connecting the  database .