Radiohead are a British alternative rock band that had most of its fame stemming from the 1990s and 2000s. They are one of the most influential bands of those decades, helping to define the sound of many alternative and indie rock bands to come. Their 1997 album, OK Computer, was, at the time, their most ambitious project. Experimenting with new recording techniques, sound effects, and working with various concepts, it is often considered their masterpiece.
The album went in and out of many phases. At one point the album was supposed to have a music video for every track featured. This idea was later on scrapped for financial reasons, but one music video for the song "Let Down" ended up getting finished. The video has never been released because Yorke thought it was "shite".
The video's producer included the music video for a very short while on an online portfolio of his, albeit in a very early unfinished form. About a minute and a half of the song is still missing, the graphics aren't fully synched up with the music, and its generally considered to be "not much of a loss" by most Radiohead fans. The video was removed not long after due to Thom Yorke demanding it to be taken down.
To this day, the full version of the video has never surfaced. The rough version can be found on YouTube, which was considered a miracle since 1997 internet capabilities were low and the odds of anyone having downloaded the full video were not very likely. Radiohead finally explored the concept of music videos for an entire album with their 2003 effort, Hail to the Thief.
Update Status: Found
On March 26, 2016 YouTube User Vini M uploaded the video in its entirely in higher quality. Giving a link to one of the companies who made the music video's website.
Video Link: https://www.youtube.com/watch?v=DNNNSYgmaYs
EDIT: Unfortunately, [Merlin] Beggars blocked the link two months later, however, the lower quality link is still accessible. It is still found, even if the higher quality version is blocked.