Auto hiding scrollbars and useless online help even when you don't have an Internet connection. Ah, and gray on gray, 1px borders and usage of titlebars as window content. And Automatic Updates, Automatic Restarts, Automatic Encryption (they know the key), Automatic ID ( you are a good citizen and don't want to make anything stupid).
The architecture has been changed fundamentally. AFAIK the old windows 2000 had flaws beyond repair. On the other hand the UI overlay build on UI overlay built on UI overlay, making everything a html page etc was terrible direction
God WinME was such hot garbage. Windows 2000 Workstation ran everything that ME ran. I fucking gamed on it, and did everything. It was faster and more stable, than ME. I never understood why people I knew who were computer nerds ran that steaming pile of shit.