Teemu Keisteri (born 22 August 1985) is a Finnish visual artist and DJ who is known for his stage persona Windows95man. As a visual artist, he gained recognition in Finland for creating the character Ukkeli (lit. 'Old man') in 2008. As a DJ, his artistic style and appearance draw inspiration from the late 1990s, during which the Windows 95 operating system was produced.

Keisteri participated as Windows95man with Henri Piispanen (Pasa, Kontio Polaris) in the 2024 edition of Uuden Musiikin Kilpailu, with the song "No Rules!". Despite finishing last in the jury voting, he came first overall with 313 points thanks to the televote in Finland. He was thus selected to represent his country in the Eurovision Song Contest 2024. In Eurovision, Keisteri and Piispanen placed seventh in their respective (first) semi-final with 59 points, and they qualified to the final, where they placed nineteenth with 38 points.

Under Windows95man and alongside Piispanen, Keisteri released several remixes of "No Rules!", and he is now playing a Finnish summer tour and a US tour in early 2025.

Windows95man released a new single called "Paperclip", an ode to Microsoft Word assistant Clippy, on 6.12.2024. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.