I read this, but it doesn't address one question I've had about this (I'd comment on it, but my rep isn't high enough):
When changing the ODD Drive Letter from D: to E:, I get this message in Windows 7:
Some programs that rely on drive letters might not run correctly. Do you want to continue?
What programs specifically need to address the D: drive from the aspect of an ODD? I was of the impression that most programs can dynamically work around this, especially since most developers account for the possibility that the ODD isn't always going to be assigned to the D: drive letter? Also, I don't have any backups, batch files, VBScripts or any other user-manipulated variables that would reference the D: drive, at least, not to my knowledge.
So would it be safe to assume that I'm not doing any harm by changing my ODD to the D:\ drive letter?