MaxLV: Only once has Microsoft really stuffed up an upgrade of Windows, and that was Windows ME, IMHO.
I bought Windows Millennium Edition on the day of its release.
The man in the shop asked me "Do you really want this?" Wise man.
I installed ME and hated it for 24 hours, before uninstalling it.
I destroyed the ME CD because there was nobody I hated enough to give it away to :)