Error INS00104 while installing BO 4.0 SP4

I am trying to install BI 4.0 SP4 with Oracle 10g R2 32 bit for repository on Win 2008-64 bit R2. I am getting error during installation ; "Database Access Error , Reason loading shared object failed. First tried to load library oci and failed to load because of error:[is not a valid win32 application]. Second tried to load library oci.dll and failed to load because of error:[is not a valid win32 application]. Cannot verify DB login information. [INS00104]. Would you like to correct them?" Not able to understand what is wrong. How do we install it. Anyone's early help will be highly appreciated.

Thanks & Regards

Piyush