@lifetec is right, usually laptop manufacturers alter their drivers.
Due to altered drivers, the laptop users are forced to install the drivers provided by the manufacturer for the best garantee of proper functioning. This does not mean you can't install the drivers from Nvidia directly, but when you do this you sometimes may expect problems with the drivers.
For the time of troubleshooting, please install only the drivers your manufacturer provides, after troubleshooting you can install any drivers you want of course
Unfortunately, there are some dumps corrupted (don't know why), but the last 4 non-corrupted dumps (back to 23th) mentioned your nvidia video driver.
Please install the drivers provided by Dell.
*** WARNING: Unable to verify timestamp for nvlddmkm.sys
*** ERROR: Module load completed but symbols could not be loaded for nvlddmkm.sys
3: kd> lmvm nvlddmkm
start end module name
fffff800`67680000 fffff800`6829b000 nvlddmkm T (no symbols)
Loaded symbol image file: nvlddmkm.sys
Image path: \SystemRoot\system32\DRIVERS\nvlddmkm.sys
Image name: nvlddmkm.sys
Timestamp: Wed Dec 16 15:03:30 2015 (56716F32)
Translations: 0000.04b0 0000.04e4 0409.04b0 0409.04e4
I would also want to ask you to uninstall Avast and use Windows Defender as alternative while troubleshooting for testing purpose.
Avast - Uninstall Completely - Windows 7 Help Forums
Regarding DB3, have you since removing those drivers installed drivers from Dell?
ffffd000`224a6838 fffff800`d43832ddUnable to load image \SystemRoot\system32\drivers\aswSnx.sys, Win32 error 0n2
*** WARNING: Unable to verify timestamp for aswSnx.sys
*** ERROR: Module load completed but symbols could not be loaded for aswSnx.sys