System clock and virus definitions in 2008

For some reason, a few weeks ago  I noticed my windows system clock had reverted back to 2008! And then I got a popup box from Norton saying definitions out of date, I checked those and they to have apparently never been updated since 2008! This isnt true but for some reason this issue has occured. Not sure if its windows or norton. But any ideas if its a known issue and anyway to work around it as its quite annoying.