It begins with a standard installation screen and the classic Windows XP setup music.

At 66% completion, the music stops, replaced by a creepy chime, and an error message claims it cannot copy "ntdll.dll" and will use "666.sys" instead.

The Scratch community has produced numerous remixes and original takes on this theme:

Many projects are explicitly labeled as "Simulators" to reassure young users that the "virus" is just a game made with code. Windows XP Horror Edition 1.1 - Remixes - Scratch - MIT