Just some notes from a recent problem, now solved, that might help the next poor soul who encounters it:

At some point recently, my install of Toad for db2 on Win7 64-bit got fubared. I tried various re-installs, reboots, etc., of Toad, IBM db2 drivers, etc. Somewhere in that process, during one of the re-installs of Toad, I got the following error, after which the install would refuse to proceed and then unwind:

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