If your computer hangs while trying to access files or programs, you can try the simple steps below to reboot your system without actually rebooting it.  However, if you still experience the problem, then I would recommend performing an actual reboot of your system.

1.Press CRTL + ALT + DEL

2.Go to the 'processes' tab and click explorer.exe once to highlight it, then click 'end process'.

3.Now, click File >> New Task and type: explorer.exe

4.Click OK

Everything should be working fine now!