A short memo on how to clean up your previous installation on Windows:
0). Stop all the Oracle Related Service if you have the database installed
Control Panel -> Adminstrative Tools -> Services
1). Remove all the Oracle related ODBC Data Sources.
Control Panel -> Adminstrative Tools -> Data Sources (ODBC)
Remove all Oracle related User DSN/System DSN
ODBC driver hooks up with the oracle dlls which blocks you to remove Oracle components
2). Reboot
3). Run the oracle installer to remove whatever can be removed.
4). Remove the Oracle registration key with regedit.exe
HK_LOCAL_MACHINE/Software/Oracle
HK_LOCAL_MACHINE/System/Services (if you have the database installed)
5). Reboot
6). Remove the Oracle Folders
Typically c:\oracle or c:\orant & C:\Program Files\Oracle
Now you are clean and ready for a reinstallation.
