Failed to read/update the registry for the BO XI R2 Critical Hot Fix

We are trying to apply service pack 4 for the BO XI R2 Sp4 for SAP Integration Kits and received the following error message during install and unable to proceed:

"Failed to read/update the registry for the BO XI R2 Critical Hot Fix for Partner Integration Kits"

We had applied a Critical Hot Fix about one week ago and it might be causing the error. How do we uninstall the Critical Hot Fix if it is indeed causing the problem?

Additionally, we have uninstalled the Integration Kit and reinstalled it hoping it will solve the problem but it didn't.

Any help will be greatly appreciated.

Thanks.