I just spent 2 days troubleshooting the installation of the IBM Client Access V7R1 ODBC driver on SQL Server 2008 R2.
So if you need to install or upgrade this ODBC driver, here are some tips.
– Before starting the uninstallation, stop all SQL Server services
– Use cwbunins.exe instead of “add/remove programs” to remove current version.
– Cleanup manually all folders and registry keys related to IBM.
– Perform extra reboots in between actions.
or even better: get IBM onsite to do the installation themselves.