My laptop shut-down by itself and its now weird

Wondering if any1 can help..

My laptop shut itself down and when i turned it back on things where a little weird.
1. The date was set to January 2009 and the time was wrong
2.The tray icons on the bottom right were in the wrong order
I don't know what could have caused this but i've done a virus scan and nothings came up.

P.S. I have a usb wireless adaptor plugged in. It picks up other networks but mine and when i go to network and sharing centre there is a red X beside it.

I appreciate any help and advice

Thats what i got from that..also my laptop seems to be going slower now!

Check your BIOS settings. It sounds like CMOS/BIOS battery has failed and the BIOS has lost its settings. Was it running on battery when it shut down? You haven't filled in your system specs, that would help, especially the make and model of laptop.

I had the charger plugged in. Its an Acer Aspire 5738z Pentium Dual-core 2.1 GHZ, 3GB RAM

OK, if it was plugged in then it may have been a hardware fault. A hard drive failure or maybe an overheat condition. If the CPU is overheating it may down clock and run slower. That would slow everything down. Are the cooling vents clean and dust free? Is the cooling fan running OK?

Yeah. It was only 2 weeks ago since i applied a new coat of thermol paste to the CPU and cleaned the fans out. I'll check the bios settings when i get home to see if it could be a battery issue.

How old is the hard drive? You may want to run a diagnostic on it. If you know who made it you can go to the manufacturers web site and download a free utility to check it for errors.