There has been a big problem installing Oracle8i or higher on windows XP. It was a major problem when i started my project. i had used Oracle 8.0 some time back with windows98 but this problem wasnt there. This problem is kinda weird. Once the system is restarted after the installation it says “Oracle not available…” The problem is that the tablespace or database would not get mounted there might be some .ora files which would have got currupted. This is a big problem with oracle8i on windows XP.
The solution is as follows:-
1) go to command prompt, get into the installed drive. get into bin directory
2) Type the command to get into the Servermanager i.e “svrmgrl”
3) your prompt will now change to svrmgrl>
4) execute the command “connect internal”
5) you can see “Connected” popping on your command prompt
6)Then finally type “Startup”
7) This will mount the default tablespace or database for you.
close the command prompt and login through the start->oracle->application Development
->SQL Plus provide the user name and password, Now you should be able to get into the SQLServer to process your Queries.