Y2K Joke is a free, harmless prank program from RJL Software that simulates a Y2K (Year 2000) bug diagnostic. It pretends to scan and fix your BIOS, mouse, and monitor, changes all letter Ys to letter Ks in the display, and even includes audio effects that claim to detect an error requiring you to tilt your desktop on its side. It is a nostalgic throwback to the millennium bug panic of 1999.