I assume you updated your laptop from Windows 7. When did this problem start? Can you boot up your computer? Does your computer work for a while and then freeze, or does it freeze right away? Have you made any modifications like adding memory or a new hard drive? When you open up Task Manager, how much CPU is being used?
Also try a cold boot. Unplug your AC adapter, remove your battery, and press the power button for 10 seconds. Wait 10 minutes, install your battery, plug in your AC adapter if necessary and press the power button to boot.