Generally a system crash is a private affair, but the BT Tower, one of London's tallest landmarks, spent much of the weekend displaying a Windows error message in a very public fashion.

The building, originally known as the Post Office Tower, is famed for both its revolving top floor and, more recently, for the banks of LEDs at its summit that act as a very prominent billboard. Sadly for BT over the weekend it was showing what looks very like a Windows 7 error screen.

"Choose operating system to start or press TAB to select a tool: (Use arrow keys to highlight your choice and then press ENTER)."

View from the top of Broadcasting House.

The BT Tower needs resetting!



I’d love to think they’re in their own endless helpline queue nightmare, waiting for a technician...#karma#haveyoutriedturningitoffandon@BTCare pic.twitter.com/Rzl4xu93Sd — Robert Coxwell (@RobertCoxwell) April 6, 2019

That BT is running a soon-to-be-defunct operating system for its display isn't particularly worrying. But the fact that it took nearly a day for an engineer to come in and fix the problem suggests BT's occasionally tardy service isn't only for its customers, but also for corporate matters.

"A technical issue caused the infoband on the BT Tower to display an error message which has now been fixed," the telco told ITV. ®