I have the same problem too!
However, I have found that I can install and run the app without reboot if I disable ALL my security apps (AVG 7.1 Pro, Zone Alarm Pro, SpySweeper, RegDefen, SpyCatcher, WinPatro). Unfortunately, I can only get through one reboot before WB reverts back to insisting that I reboot. If I disable all the apps that I mentioned and do repair installation, I can run it again (without reboot). One thing worthy of note in this is that I get a completely unhelpful error message every time I install that informs me that there has been an error and I should try again from an account with admin privileges. NB that I DO have full admin privileges and have verified this a number of times. I click "ok" to clear the error and installation continues. What's non-helpful about the error message is that there is no indication as to what part of the registry I don't have access to, so I can't go looking at specific keys to see if I need to change privileges on them.
Note, too, that when I'm using WindowBlinds the System Information tab from the configuration dialog reports that all systems are go and that WB is correctly installed.
Finally, I've checked the registry key that was suggested earlier and it doesn't exist in my registry... Hmmmmm... just checked it and I didn't have read/write permission for the "notify" part (what is it, a branch, node?). I've changed that and will do a complete uninstall/reinstall and report back.
Thanks,
Mike