Computer Frustrations

I got home from work yesterday and was on my computer and notice a couple weird little glitches in what it was doing but didn't think much of it then msn wouldn't connect again just assumed that it was a problem with msn I asked my daughter who had been on my computer earlier ion the day if she had changed any settings she promised me she hadn't. So I turned my puter off and went to bed. Turned it on this morning and tried to connect to msn and no go and then my anti virus program was saying it wasnt working so I tried a couple of things ot see if i could fix it ended up uninstalling msn and dl another version but still nada at this point i had to go to work. So I got home from work today and fiddle for another hr and still nothing then windows update tells me there is an issue with the date and time on my computer........... YES my lovely daughter had been planning her Aug 2009 holiday yesterday had managed to change the date on the computer to August 2009 it took me 2 seconds to fix and for everything to be working normally this about after almost 3 hrs of frustration uninstalling and reinstalling programs.