Standby option inactive

My problem is that I can't use the "Standby" option. When I click on Start -> Turn off Computer, the Standby option seems inactive/disabled. The problems start appearing since last couple of days, and I don't remember if I changed anything that might have led to this problem.

Thanks in advance!

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Mubashar

<font color=red><i>"All delays are dangerous in war."</font color=red></i>

for the hidden file-problem,
Go to registry editor by running regedit in the run box.
Go to this key:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\Advanced

In the right hand area, double click hidden and change the value to 1.
I think it will work
thank you