Please uninstall Avast and use Windows Defender as alternative.
Avast - Uninstall Completely - Windows 7 Help Forums
To clear this up
*** WARNING: Unable to verify timestamp for aswMonFlt.sys
*** ERROR: Module load completed but symbols could not be loaded for aswMonFlt.sys
NTFS.sys is a driver for the file system a.k.a. hard drive, if this driver is causing problems in most cases it means the hard drive is giving problems or something related to the hard drive.
Bluescreenviewer stated a bug check code of 0x0000003b (video?). And highlighted the NTFS.sys+11b88 and ntoskrnl.exe+14cfe9 as the cause?
Ntoskrnl.exe is a driver used in the boot process, this driver is extreme rarely the cause as it is usually only flagged because it is the last active. If ntoskrnl.exe is truly the cause you would experience a lot more problems.
The 0x3B means an exception has occured. Normally, a driver stores data in the memory for later use. When a driver is trying to access the data it appears this data is corrupted. The driver cannot use this data because it didn't expect it, the system has noticed it and called a bugcheck (bluescreen) to prevent data loss. The driver cannot use the data, because what would have happened could cause many problems, but the driver would still have used it.
Note: it could mean the memory is the cause or the 1st driver has stored the data in the wrong memory address.
This is the case I see a lot, but it is usually with a driver and memory, not with the file system.
Let me know how it goes