I usee windows update to install the SP2 upgrade. It appeared to run and install like it should, then it requested to restart the computer to finalize the install. my Toshiba A200 series shut down and now it wont start up again. I have tried with it plugged in and also with just battery power,...the battery light is blue( fully charged). when I push the power button, the Power light comes on for about 5 seconds then goes out again. the screen stays blank. I am rather irritated that my laptop was working perfectly up until I did the upgrade.