OK, I'll repeat it once again
This is an internal tool that wasn't really meant for public (which doesn't mean it's any secret, just that it was build rather quickly, without any attempts to make it bulletproof or user friendly). You asked for it, so you got it... but there wasn't any additional time spent on that.
Its main purpose was to trigger the autosandbox pop-up, that's all - nobody actually used to it verify sandbox functionality (OK, maybe once, but that's really all). Red-framed window --> OK, no red frame --> something's wrong.
And even though I didn't write it myself, I certainly wouldn't notice the problem with C: drive - as disabling UAC is the first thing I do on my computers, I really can't live with that.