Unattended Removal of the Oracle 8i Client
I went to www.systernals.com and got listdlls.exe to help track down what was locking that dll.
Turns out it was SMS 2003.
I repackaged the uninstall of the Oracle Client. This cleaned up the registry, but I had to do some work before I could delete the files from c:\ORANT.
After the package deleted all the reg keys I ran a batch file that used listdlls.exe to find the PID (process) that was holding core40.dll. Then I had SMS stop the service for CcmExec.exe and kill it's parent process svchost.exe. Then I was able to delete the ORANT folder.