Date and time wouldn't show up in windows xp?

My OS is windows xp sp2 and just now I realized there is something
wrong with the date and time function. I tried clicking on the clock
on the taskbar and nothing happened. I went into the control panel and
clicked on "date and time". A window flashed for a second and then
disappeared. I also tried rebooting the computer for a couple of times
but the problem still persists. I scanned for viruses and spyware and
nothing came up. I also ran windows update and made sure everything is
up to date.

Otherwise the computer works normally. Could someone please help!