A second EP followed in October 2002, Happy with What You Have to Be Happy With. This featured eleven tracks including a live version of "Larks' Tongues in Aspic, Part IV". Half of the tracks were brief processed vocal snippets sung by Belew, and the songs themselves varied between gamelan pop, Soundscapes, and slightly parodic takes on heavy metal and blues.
King Crimson released their thirteenth album, The Power to Believe, in October 2003. Fripp described it as "the culmination of three years of Crimsonising". The album incorporated reworked and/or retitled versions of "Deception of the Thrush", tracks from their previous two EPs, and a 1997 track with added instrumentation and vocals. The Power to Believe reached No. 162 in the UK and No. 150 in the US. King Crimson toured in 2003 to support the album; recordings from it were used for the live album EleKtrik: Live in Japan. 2003 also saw the release of the DVD Eyes Wide Open, a compilation of the band's shows Live at the Shepherds Bush Empire (London, 3 July 2000) and Live in Japan (Tokyo, 16 April 2003).
In November 2003, Gunn left the group to pursue solo projects and was replaced by the returning Tony Levin. The band reconvened in early 2004 for rehearsals, but nothing developed from the sessions. At this point, Fripp was publically reassessing his desire to work with King Crimson and within the music industry, often citing the unsympathetic aspects of the life of a touring musician.
Despite this, a new King Crimson formation was announced in 2007: Fripp, Belew, Levin, Mastelotto, and a new second drummer, Gavin Harrison, the first new member from the UK since 1972. In August 2008, after a period of rehearsals, the five completed the band's 40th Anniversary Tour. The setlists featured no new material, drawing instead from the existing Discipline-era/Double Trio/Double Duo repertoire, although several pieces received striking new percussion-heavy arrangements. Additional shows were planned for 2009, but were cancelled due to scheduling clashes.