Yesss, That happened to me also when I install patch 10.1.0.4. in WIN2K.
Oracle install cant proceed becoz it says there are still services in used.
I even stop all the services that are running even ALL the services
not related to oracle, so no more windows service is up but still it
wont proceed. I cant understand why oracle not just display the
show-stoper services that it found open to make life easier.

What i did is reformat the server and fresh clean install everything.
Good thing its just a test server.