Nvidia drivers.

I am not a fan of the Nvidia display driver installer's old-ish look: it covers up the screen with a faux-maximized window and prints the software's name in big bold-italic Times New Roman. It always installs quickly, though, and much more so when I upgraded my card's driver from version 185.85—to my pleasant surprise (and as Microsoft has promised Vista would allow for years), installing 186.18 didn't restart the rig, as a few others have noticed.

Well, sort of. It does restart Windows Explorer, at least, and that nukes taskbar icons of programs that don't know better. A simple logoff and logon (relogon?) fixes that in a flash, and lets me finally enjoy Vista's "no-reboot" boast.