In case that you receive the following dialog during an upgrade of the Oracle Client:
You need to shut down the following services and click on "Retry":
- COM+ Event System
- Help and Support
- Task Scheduler
- Themes
To view which services have a handle open to the OCIW32.dll file you can download and run Process Explorer from Sysinternals Microsoft which you can download here.
After the installation reboot your PC to make sure that all the services you have just stopped are started by the system.
Cross-posted from
The .NET Aficionado