Hello medinarawk and Terry Wetzel,
Let me try to help and clear up some confusion for you.
There are two types of drivers in use on your Windows computer. The OS uses WDM for basic programs like iTunes, Windows Media Player, Internet Explorer. DAWs such as Pro Tools use the ASIO Driver.
Sometimes you can find that if Windows is set to a different Sample Rate than the Pro Tools session an occasional request for Sample Rate change from Windows, say for a simple beep sound, can grab the interface and change it's Sample Rate, which Pro Tools will detect and then it will relaunch.
The easiest way to prevent this is to make sure your Windows Sounds are set to the same Sample Rate as your Pro Tools Session. Do this in Start Menu > Control Panel > Sounds > Scarlett > Properties > Advanced.
Additionally I notice the OP had a different error message, where in Pro Tools Playback Engine they selected Focusrite USB Audio Driver and got "Unable to Initialize the Focusrite USB 2 ASIO Driver."
This can be caused by a few other things, such as another program using the device, sample rate mismatch with windows, or even a need for Deleting Preferences and Databases.
First you should make sure you have the latest driver, currently 2.5.1 for Windows 7 and 8 and 2.4 for XP:
http://us.focusrite.com/downloads?product=Scarlett+2i2
After install, make sure that the Windows Sample Rate is set to that intended for your new session.
Open Pro Tools by right clicking and choosing Run as Administrator. Hold down the 'N' key while loading Pro Tools. This will Launch the Playback Engine before the Quick Start.
See if you can now select the Focusrite USB2 Audio Driver here.
If you are still having trouble we are always happy to help you. Please contact us here:
http://us.focusrite.com/answerbase/contact
Best regards.