The problem started a few days ago when the recipient of an email with pictures attached informed me that a bug was also attached. I ran malware and virus software last evening and they found nothing. I restarted for the first time since then this morning (I usually hibernate) and the computer froze. On the second restart I realized that I lost control of the mouse buttons after a notice that MalwareBytes' Anti Malware program had crashed. I am able to keep the computer running by exiting MalwareBytes' from the toolbar as soon as it appears. Otherwise, the computer always freezes under the same condition on start-up.
No other symptoms are present. The computer seems to be running fine as long as I get it past that first stumbling block. I am running avast! for virus protection. I have done a number of the "clean up" tasks I found on your website.
The pictures were taken from a disk burned from our desktop, which we rarely use anymore. But that could be a coincidence.
I totally appreciate your help, and as my computer still seems to be working, I am not frantic for a fix.