The instruction at OX7... referenced memory at OX7000000. The memory couldnot be "read"

Click on OK to terminate the program
Click on cancel to debug the program

I suspect a ram module. Download a program called Memtest86.
Memtest86 - Download Page (http://www.memtest86.com/download.html)

If the RAM is OK then try a virus and maleware scan.
-AVG 2010 Free
-Malwarebytes antimalware

If that doesn't work, Restore back a month or two.

If all else fails, Reload Windows.