I upgraded my old Toshiba L45-S7423 laptop from Windows XP to Windows 8 Pro recently via CD/DVD. A couple of days later, the touchpad stopped working. although a USB mouse works just fine. The touchpad issue might be related to a Windows update that occurred about the same time as the issue appeared.
The laptop has been running Windows XP for several years without issues other than slow boot and shutdown.
Of course, I know very little about Windows 8. Any ideas on how to proceed?