1. Oracle client 10.2 is required for Oracle 10.2.
2. Recreate the connection from Spotlight connection properties after ensuring Oracle Home and Tnsname entry is set correctly. To change the Oracle Default home in the client registry.
a. Select Start | Run | Type regedit.
b. Navigate to HKEY_LOCAL_MACHINE| Software | Oracle.
c. Edit or add: the following parameters. To add a new string right-click and select 'New/String Value'.
ORACLE_HOME = enter the client path
TNS_ADMIN = the tnsnames path
3. There must be msxml4.dll and msxml4r.dll in Windows XP e.g. C:\WINNT\system32\. To install the latest MSXML Parser version, download and install the MSXML Parser from Microsoft site:
http://www.microsoft.com/downloads/details.aspx?FamilyID=3144b72b-b4f2-46da-b4b6-c5d7485f2b42&displaylang=en