The company agreed to sign the band in 2000 in the wake of the success of such well-known punk bands like Green Day and Blink-182. June 27, 2000 the band released the album Half Hour of Power. The first single the group has song Makes No Difference, which was filmed two videos. The first clip was from a movie that was filming the band and the second version of the group sang at the house party. This song was used in the movies: Bring It On, Summer Games, Frozen, King of partying and games Dave Mirra Freestyle BMX 2 'and NHL 2002. " The album went platinum in Canada.

Immediately after the release of the band went on tour, playing on stage with The Mighty Mighty Bosstones, The Offspring and Blink-182. Sum 41 released the album All Killer No Filler May 8, 2001. The first single of this the disc was the composition Fat Lip, which became a major hit of the summer and reached the first lines in the charts in the U.S. and other countries. Nokia has even announced that Fat Lip – most used the melody for mobile phone 12. At the beginning of the clip Fat Lip the group sings the song What We're All About without musical accompaniment.

The single also included in the track listing for the game of NHL 2002 EA Sports along with Makes No Difference. The band's popularity has increased significantly because of the performances on Warped Tour this year. Later, two were released Other singles: In Too Deep (in a comedy clip of this song the group has participated in diving from the springboard) and Motivation (in the video group sang a song in the attic).