Comodo HIPS shouldn't be a problem, follow my advice (Reply #6).
Hmm, but Cavshell.dll might be , It described itself as "..Anti Virus" when I ran a shell extension checker. (Disabled temporarily as precautionry measure. - Will be running a FULL Scan shortly.
RESOLVED - In respect of Avast involvment, so I'll be directing further comments in the directions of other vendors....
Thank you for your patience.
Feature Suggestions for the Paid/Pro version,
*A scan on "crash"-tool that can advise what went wrong in an app that crashed (such as explorer.exe), and possibly scan the modules mentioned in a stack trace for odd signatures. (I find the normal "X has encountered a problem" dialog a little misleading sometimes.