Networked computers Win-update reboot 2 black screen

I'm asking for help because for the last four weeks, I've been plagued by black screens on three networked computers when rebooting from Win updates. One of the computers is still unbootable. The other two have booted to a black screen each week after Windows updates, but *so far* restarting and choosing startup repair has corrected the issue each time.

I'm concerned about malware because of the coincidence of such similar issues on three previously stable systems without a lot of overlapping software. Also, when I was first researching the issue it seemed like every website was chock-full of anti-malware and system tuneup ads, all strangely uniform and bland.

I'm attaching logs from an HP Pavilion dv7-1247cl Vista 64-bit laptop running AVG and WinPatrol. I'm posting logs from this computer because it's the most convenient of the three. After the second week of black screens I ran Malwarebytes and quarantined something called pup.optional.downloader on this computer. Everything seems normal except for having to run startup repair after every Windows update.

I'm hoping to fix whatever is causing the black screen each week, and to find some clues as to what might be affecting the the other two computers. If there is malware, I need to figure out how to handle my files recovered from the non-booting computer (external drive, plus those shared thru Dropbox.) If there's a better way to approach the issue, I'm open to suggestions. Just let me know what info is needed. I really appreciate the help!

Lyn

******
Supplemental Info on the other computers affected:
A VAIO Win 7 64 bit laptop running Avast, PrivateFirewall, and Threatfire stalls on reboot to aswrvrt.sys stalled to black screen four weeks ago and I've tried safe mode, last known good configuration, system restore, and startup repair. I can access files with Hiren's but it's otherwise unbootable.

The third computer is an HP Pavilion Vista 64-bit desktop running Avast. The first time it went to black screen I did a safe mode log with command prompt, and found that it was also stalling at aswrvrt.sys. It was able to boot to Windows after running startup repair.

The 2 HP computers share files on the network. The VAIO didn't share files on the network, but some MS office, PDF, and JPG files were shared with the HP desktop through Dropbox.

End supplemental info

******************

 

Thanks for taking a look at this for me; I appreciate it. I was away for the weekend but will be checking back more often now that I'm back.

I'm attaching jrt.txt.

Thanks,
Lyn

 

Things are running fine on this computer except for the weird stall to black screen when rebooting from Windows updates, and having to run startup repair to get Windows back. If it follows the pattern of the past few weeks, it should stall to black screen when it's installing any patches this evening. Makes me nervous.