Oracle not Available or shared memory realm does not exists

when i tried to login to oracle using

username = scott

password= tiger

geting an error i.e.  Oracle not Available or shared memory realm does naot exists.

to solve this error

you have to follow just few steps:-

Step 1:-

sql> connected as sysdba;

and password is sys;

Step 2:-

sql> startup  nomount;

it give message   like this

ORACLE instance started.

Total System Global Area 113246208 bytes

Fixed Size 787708 bytes

Variable Size 61864708 bytes

Database Buffers 50331648 bytes

Redo Buffers 262144 bytes

Step 3:-

sql>alter database mount;

Step 4:-

sql>alter database open;

Now Problem solve....

now youe oracle is ready...... and start using...