I contacted Microsoft support and they told me that avast! was causing the BSOD. When I uninstalled avast! and installed MSE my BSOD disappeared. Here is the conversation:
http://social.technet.microsoft.com/Forums/windows/en-US/2109a549-819c-4dda-a247-93f1dd7fd54f/bsod-systemserviceexception-atikmdagsys?forum=w7itprohardware
Here are my minidump files (if necessary): https://mega.co.nz/#!UgVn1Aib!aFflXIrMvT-aMVbXgzZm7jBljqgf4QIN3QdClhG7ZyE
I am running Windows 7 Home Premium 64 Bit with Service Pack 1. Any help? Thank you.