The CAUSE of this factor is "UAC" better known as "User Account Control". 

"User Account Control" notifies you before changes are made to your computer that require administrator-level permission.  The default UAC setting notifies you when programs try to make changes to your computer, however you are able to adjust these settins and change how often UAC notifies you.

NOTE - If a computer is set to receive Automatic Windows Updates at a specified time, User Account Control affects Microsoft SQL Server in terms of connectivity (SQL Server login) and in limiting access to resources on the administrators’ access control list (ACL). 

The primary purpose of UAC is to ensure that users and applications are granted the lowest level of permission they require to complete their tasks and in this case, the task is Updating windows which stops your SQL service and does not restart it automatically. 

"For Example" If your computer is set to receive automatic updates everyday, UAC will stop your Paper Tiger service every day producing an Error 5 Message causing you to restart your Paper Tiger SQL service Manually.  If UAC is enabled, the system will automatically restart itself after updating and UAC acts as a firewall prevention for the service to start because the prompt doesn't automatically appear, asking "Do you want to allow the following program from an unknown publisher/program to make changes to this computer during Auto Updates".  This causes you to enter your services and start manually because Windows Updates have taken place.  Of course if windows update is scheduled to run at a time where you are away from your computer, you will not see this prompt and SQL will be haulted because admin password has not been provided.

Solution

Ensure that you set your Windows Updates to automatically update "ONCE PER WEEK OR EVEN LATER" on hours where you are around your computer, e.g. 12:00PM.  If you desire to apply windows updates at a time where you will be away from your computer, you may want to disable UAC.    

Adjust Settings to Automatically Update Windows

• Open up the start menu by clicking the windows button at the left lowerhand side of the screen.
  

• Then type in "Windows Update" inside the Search Panel.

• Click "Change Settings"

• Here you will need to "adjust the time" to a time where you will be able to accept permission if UAC is still enabled.  It will also help to "install updates one day per week opposed to updating every day".

To Disable UAC

• Open up "Control Panel", and type in "UAC" into the search box.  You'll see a link for "Change User Account Contrl Settings".

• Simply drag the slider up or down, depending on how often you want to be alerted.  In this case, placing the slider to "Never Notify" would be disabling UAC.

To see how to restart Microsoft SQL Server, click here or for Wiindows 7, click here.