Arguably every election that brings in a new government is a reboot. A revolution is more like wiping the drive and installing a new OS.
In the UK, Governments change but Parliament persists. The basics mechanism of state are unchanged until a new Govt defines and votes through new policies. Unlike the US, the UK's civil service doesn't substantially change as a result of an election.
The last really significant change to Parliament was perhaps the 1832 reform act which got of rotten boroughs - constituencies with few if any voters that still returned MPs. Since then the House of Commons has gained primary over the House of Lords, whose main role now is delaying/modifying Govt proposals. The last big reboot was the Restoration.