Microsoft Plus!
From BetaArchive Wiki
The Plus! pack was an expansion pack originally released for Windows 95 and later for Windows 98 and Windows XP. It contained themes, screensavers, a drive compression tool, Internet Explorer and a program scheduler. The popular Windows Pinball game also made its debut here.
Many betas of the Plus! pack were included in early builds of Windows Chicago. A canceled release was the one for Windows 2000 (then known as Windows NT 5.0) as the Antitrust docs indicate.