2K-tan, also known as Futak Tan (二系たん), is a personification of the Microsoft Windows 2000 operating system from the OS-tan series, a Japanese internet meme and fandom where various operating systems are depicted as anthropomorphized characters. 2K-tan is portrayed as a calm, mature, and reliable young woman, often depicted with an office worker's appearance, reflecting the stability and professional use of Windows 2000. She serves as a supportive and dependable figure among the other OS-tans.