Windows 7: W7 User-Login-Field: takes a long time to appear

Hi,

from one day to the other, the Windows 7 login button takes a long time to appear when booting windows.

I can see the blue screen - but empty.
After several minutes, finally the User-Login-Fields appear.
Before, it apeared in less then 30 sec after switching the laptop on.

Before I have cleaned my C hard disc with the automated hard disc cleaner that appears when you click with the right mouse button on "C:" and then "Options". The system offered me several temporary files to delete and I did so...Maybe I deleted something that was necessary for the booting process?

By the way, the problem appears when I close my laptop in the stand by node and reopen it: blue screen and minutes until the login-Fields appera.



Any idea?

Thanks
T