To remove the message boxes / windows that appear while Windows is loading do the following:
- Start > Run > gpedit.msc > Click OK
- In the Group Policy window select Local Computer Policy > Computer Configuration > Administrative Templates > System.
- On the right, double-click the "Remove Boot / Shutdown / Logon / Logoff status messages" setting and select Enabled, click Apply and OK.
Restart your computer and the loading message windows / boxes will not appear.
NOTE: You may also want to disable the Welcome screen: Control Panel > User Accounts > Change the way users log on or off > uncheck "Use the Welcome screen" > click Apply Options.