It looks like there is a specific issue with this system, which is stopping GBW launching properly. Short of rebuilding this system, the other thing you could try, is using a utility such as Procmon to monitor the launch of GBW on a working system, and compare with the system where it hangs. My guess is that there is a file version mismatch or something amiss in the registry.
You could also try an uninstall, followed by a registry wipe of the obvious keys, and a logged reinstall. The log should report whether there are any files that are not installed due to a version conflict.