windows 8 cmd.exe and notepad.exe random frozen.

in windows 8 when open cmd.exe or notepad.exe, and let the windows stay for a long time, the cmd.exe and notepad.exe window will be all frozen, and you cannot open a new cmd.exe or notepad, and even taskmgr.exe cannot be opened, so it is difficult to terminate these processes.  When I do some checking, and found that the "Console window Host" process under windows processes was not response. Anyone encounter this issue?