While touring in support of their debut studio album Hope Is Important (1998), the band wrote and recorded its follow-up in stages.

Sessions were done between May and November 1999 at a variety of studios: AIR in London, Jacob's in Surrey, Rockfield in Wales, and Electrical Audio, Chicago.

Initial recording with Bob Weston resulted in unremarkable material, by which point they switched to working with producer Dave Eringa.

100 Broken Windows received generally favourable reviews from music critics, some of whom praised the songwriting and progress from their previous album.

[5][6] Woomble said they didn't want to be viewed as "just as a rowdy night out for teenagers"; with the creation of "Little Discourage" and "Roseability", the band had a newfound confidence.

[12] Discussing the title, guitarist Rod Jones said Woomble had written it in a book sometime prior, and that it dealt the album's topical theme of dissatisfaction.

[14] Jeff Jackson of Sonic said the lyrics bounce between "straightforward declarations and enigmatic wordplay, the songs unfurl their meanings in short bursts and volleys".

They subsequently changed the song; its lyrics were intentionally vague, spurred on by the opening line, which Woomble had written on its own at the top of his notebook.

[19] One of its lines, "shed a shade of shyness" was taken from a live review about Woomble, which he felt "link[ed] together public and personal opinion".

[18][29] During one weekend, Eringa was working as a sound engineer for a Manic Street Preachers show; Idlewild got drunk in the studio, attempting to cover "Save Tonight" (1997) by Eagle-Eye Cherry, and wrote "Mistake Pageant" in the process.

[16][31] In July and August 1999, Idlewild played a handful of shows in mainland Europe and the UK, including an appearance at the Reading and Leeds Festivals.

[38] Two versions were released on CD: the first with "Meet Me at the Harbour" and "West Haven", while the second featured "Forgot to Follow", and a cover of "It'll Take a Long Time" (1972) by Sandy Denny.

[43] 100 Broken Windows was promoted with an instore performance at the HMV shop in Edinburgh, a one-off gig that was broadcast on Japanese TV, as well as appearances on Later... with Jools Holland and Top of the Pops.

[36] The band played a handful of instore performances at Virgin Megastores, prior to appearances at the Glastonbury, T in the Park, Witnness, T on the Fringe and Reading and Leeds Festivals.

As James and Alex were busy, the band settled on Gee, who had previously worked with other acts on Parlophone, such as Coldplay and Radiohead; they invited their fans to appear in the video.

[36] "Roseability", "Actually It's Darkness", "Idea Track", "Little Discourage", and the remix of "Rusty" were included on the band's third compilation album, The Collection (2010).

Entertainment Weekly writer Brian M. Raftery said Woomble's voice was "backed by rousing punk guitars and a ceaseless energy.

"[63] Octavio Hernandez of La Opinión said it was an "energetic recording", with Woomble's " brilliant voice and a rhythmic skeleton of great flavor".

[16] The staff at NME said melody is "now paramount over velocity, the rough edges of reckless spontaneity smoothed by the high-gloss patina of responsible coherence".

"[18] Keith Gwillim of Stylus write that the band made music that is "all bluster and belligerence on the surface, but goes much deeper", showcasing that they were capable of "stealing from the past and making it your own".

[19] Pitchfork joint reviewers Beatty & Garrett expected a repeat of Hope Is Important and were "completely [...] surprise[d]" as it had "[n]o more screeching.

"[66] In The Rolling Stone Album Guide, Chris Ryan wrote that the band "grows up and gets smart", greatly "step[ping] up in song-writing quality, as melody takes precedence over noise".

[68] AllMusic reviewer MacKenzie Wilson noted that the band "scale back a bit" on the album, while showing they had "grown up".

[62] Chris Lorraine for Blender said that while it was a "melodic, chorus-catchy disc", the band's "need to kick into a loud anthemic chorus on each song feels a bit by-the-book".

[72] BBC Music's Mike Diver saw the album as a "game-changer" that "stamped Idlewild's identity as a highly literate, immensely able outfit whose melodies had evolved into true earworms".

[71] The Skinny's PJ Meiklem noted that a few of tracks had "all the melodic clues" that would be expanded upon with their next album The Remote Part.