Here are some things you can do that may fix the problem you are having with your computer.
Open Task Manager
Simultaneously press [Ctrl] [Alt] [Delete]. You will see a list of all tasks (programs) currently running. You may notice one program has "Not Responding" instead of "Running" listed next to it. Select this task and click the End Task button.
Another dialog box will open stating that the program is not responding. Choose End Now to close the program.
Reboot your computer (Warm Boot).
Resetting a computer that is already turned on
Press [Ctrl] [Alt] [Delete] once to open the Task Manager.
Press [Ctrl] [Alt] [Delete] again to restart the computer.
Shut down your computer (Cold Boot). Start-up of a computer from a powered-down state.
If you restart your computer and the problem isní»t resolved, make an attempt to completely shut down the computer by pressing the power button. Let it set for 15-30 seconds then restart the computer.
You have run out of disk space on your computer. Music files, movies, digital pictures, and other big data files can fill up your hard drive. To check for disk space:
Open My Computer. Right click on the C: drive and select Properties from the shortcut menu. A pie chart will appear telling you the used and free space.
Try running the Disk Cleanup Wizard. This utility can tell you whether you are running out of room and help you clear away some space. Click the Start button and choose Programs | Accessories | System Tools | Disk Cleanup. Choose the disk to clean up (C :) and let the wizard do the work.