First, make sure you do not inadvertently disabled the touchpad. There is a key combination Fn including, it turns on and off.
What other keys you pressed? Probably one of the function keys (F1 through F12), although it may be something completely different. Examine the keyboard, paying attention to small icons (usually blue) on one of the buttons and seeks an icon that resembles the touchpad.
Unfortunately, not all icons touchpad are easy to decipher. If you do not know what it is, write in Google the model number of your PC, along with disable touchpad.
If this does not solve the problem, go to the panic of the touchpad. Go to the Start menu and type mouse settings. Select Change mouse settings.
Once in the dialog box, click on the tab dedicated to your touchpad (the name changes from model to model). Make sure everything is enabled. If there is a Settings button, make sure it is on.
If this does not help, you may need a new driver. Enters the site of the manufacturer of your laptop and find the model number and the words touchpad driver. See if the driver is available for download, and install it.
If none of these suggestions work, it's a hardware problem. In that case, you have two options: send your laptop to the repair or buy a wireless mouse for use with your PC.