Pro Tools 9 Not Responding

[jpaul1988]

I have a Toshiba Satellite C875, Intel Core i3-3120M CPU @ 2.5 Ghz, running on Windows 8.1 64 bit operating system. I have Pro Tools 9 and update 9.06 installed. I use an mbox3 and an maudio fasttrack ultra 8r. I ran Pro Tools on June 16 without any incident. Today, I attempted to run pro tools and it will not run. With the mbox3 the error stated there was an underflow problem, so I changed the playback engine to 512 samples from 1024. Pro tools still does not run. I uninstalled all ProTools components and reinstalled PT 9 and PT9.06. Using the mbox3 again, protools wouldn't even play, and displayed no error message. It locked up the entire computer. I switched to the maudio fasttrack ultra 8R with a different USB cable and PT still would not run. Since June 16, there have been 10 Windows Defender definition updates, one Update for Windows 8.1 for x64 based systems, and one Synaptics PS/s port touch pad update. Any suggestions on how to correct my issue?

Thank you.