windows update cannot work

symptom:

windows update cannot work.   need you restart your computer.

solution:

the windows update service is start, and the start mode is automatically.

run "cmd", and input net stop wuauserv,   remember to run "cmd" as administrator,  otherwise it will alrm "system error 5,  access denied"

then, run "%windir%", and located to "softwaredistribution".  then delete this folder.

and run net start wuauserv,

Now you the windows update will automatically execute.