I have AVG (licenced) and Spybot S&D on my system. Malwaytebytes was giving me false positives on some files then crashing my system. Removing the files 'let' the software continue until it found something else it didn't like, then it crashed my system again - it now runs for about 30 minutes then crashes my system without finding anything I can see. I've run AVG over the same files and found nothing, same thing with Spybot, which always found what Malwarebytes found only when I ran it over the files Malwarebytes found, it found nothing. I'd made some changes to my system so did a system restore and ran Malwarebytes again with the same result. I've looked at what's on the computer (using Autoruns) and there is nothing out of the ordinary. Things I've tried: Reseating components on the MB Replacing the BIOS backup battery System restore I haven't run chkdisk yet but I guess it's worth trying with the /f option. I removed and reinstalled Malwarebytes last night before reading your reply but have not tested it yet, but my gut feeling is that there is a problem with it as my other software isn't crashing the system, well not yet anyway.