I had a copy of Webroot secure anywhere which reported that the pdflatex portion of Miktex 2.9 a Secure but free highly useful portion of my tex/latex environment which I use with lyx to type math was bad and Quaranteed a consistent number of items.  As i have more faith in Miktex 2.9 which I have used for many years without security problems and because it appeared Webroot broke my installation despite my attempt to update the file name Database I removed it from my computer.  The first thing I did was restored the quaranteed items with no luck.  I then removed Webroot using Revo Uninstaller (it refused to uninstall) and installed avast which has given me no problem I used to have premier malwarebytes but when it blocked my access to the best free library in the world, I decided that it was more interested in anti-piracy (a large threat to vendors) than anti-virus, or anti-malware, most likey produced largely by vendors so as to ensure purchases of anti-virus software which may be in large measure  significantly useless.   I still use free software to largely block what viruses exist.  Interestingly enough this is largely a problem in Windows, I have heard little such problem on the Mac or Linux.  Unless I hear of substantial fixes I will never use Webroot again (it was on this computer because before the upgrade) avast had a problem with it and cannot recommend it to anyone because of obvious false problems.   If Webroot certified in writing that it never took any money whatsoever from vendors who wish to block anti-piracy with a bond posted as a penalty I might reconsider.   I have many more problems with anti-malware or anti-virus software than with malware or viruses themselves although they happen on rare occuasions.  Much more frequent is blocking my attempt to get useful or free books on my computer.