1. You post in the XP forum, but from the subject line I get the impression it's not an XP problem, but a Windows 7 problem. We've got a special Windows 7 forum, and that would be a far better place to post your problem: http://forums.cnet.com/windows-7-forum/
That's why I'm locking this thread.

2. If you repost there, please tell much more, such as:
a. What version of Windows 7.
b. What part or version of Oracle 10 you're installing, and where you got it from.
c. The system requirements for that part or version of Oracle.
d. Why you think it looks like something is missing. There might be an error message that's more informative than "something is missing".