How default Home is set in Windows Oracle Client?
In my windows xp client machine, I do not find %ORACLE_HOME% is set. I tried echo as well as env and that do not list the ORACLE_HOME. Hence, I saw the regedit which has got three oracle homes, 8.06, 9.20 and another 9.2 (with forms and reports). The default home is set as 8.06, but my client sqlplus and toad is taking the TNSNAMEs from 9.2 home.
When I tried installing 10g, oops, I could not set the tnsnames properly and sqlplus client is not working!
I am confused about these settings as I need to set this whenever I need different client to talk to different database. I am not a dba, but using oracle applications long time. Hence, I understand the concepts, tnsnames, and the setups etc..
Can anyone guide me the details? Please let me know where to look out for correct information, like web pages and client setups?