It very much was not. Arial has never been a default UI font on Windows, and MS Sans Serif was replaced by Tahoma as the default in 2001. Arial has been a default document font though, so it could have been Arial.
Technically, Tahoma was first distributed with Office 97 in Nov 1996, and it first became the default UI font in Dec 1999 with Windows 2000, but in regards to consumer oriented Windows, it became the default UI font in Aug 2001 with Windows XP.
It very much was not. Arial has never been a default UI font on Windows, and MS Sans Serif was replaced by Tahoma as the default in 2001. Arial has been a default document font though, so it could have been Arial.
Tahoma came in 2001? That is earlier than I thought. TIL.
Technically, Tahoma was first distributed with Office 97 in Nov 1996, and it first became the default UI font in Dec 1999 with Windows 2000, but in regards to consumer oriented Windows, it became the default UI font in Aug 2001 with Windows XP.