Doing a basic Google search using the keywords "malwarebytes quick scan" (sans quotes) these are two quotes of MWB's forum moderators in 2009, "The quick scan will find any malware that's active on the system that MBAM is capable of detecting. The only real usefulness of the full scan is detecting the occasional trace that get's missed by the quick scan, and even that's pretty rare. According to one of the developers the quick scan catches 99.9% of the malware that MBAM will detect. "All it does is scan more locations on the hard drive(s), thus allowing it to pick up traces it might have otherwise missed, but again, even that's rare because the quick scan is designed to look in all the places malware likes to hide." DA

Any anti virus test comparison would likely be obsolete within a week because virus activity is a moving target. From Snidely's link: Microsoft canâÂÂt be too happy with its security software right now: For the second time in a row, the companyâÂÂs Security Essentials failed to earn certification from AV-Test, the independent German testing lab best known for evaluating the effectiveness of antivirus software. Then the very next paragraph: These results are noteworthy because Microsoft Security Essentials is currently (as of December) the most popular security suite in North America and the world. If MSE was as doubtful as the article suggests surely a large portion of those subscribers would move to something deemed safer. The second from last paragraph suggests biased reporting as it notes MSE was only one of three that failed yet they did not bother naming the other two companies. Plus if you click the second link in that paragraph you will note the tests appear to be from November/December 2012. That is months ago and a huge swath of viruses (or virii) have been released since then

just to clarify you do have the computer turned on at that time period daily correct? it will not scan when off or when in sleep mode. It will perform the scan at the next scheduled time. You did not tell us if you are running windows 7 but this is how to find the sleep mode option It can be found by launching "taskschd.msc" from the start menu. You then expand "Task Scheduler Library" to find "Microsoft". From there you will see "Microsoft Antimalware" and then "MP Scheduled Scan". Under the properties select the "Conditions" tab. Under the "Power" section check: "Stop if the computer switches to battery power." and "Wake the computer to run this task" If you are using xp go into the control panel and open up the Task Scheduler. Then select "Advanced" from the pull down menu and then select "View Hidden Tasks". you should see a task named "MP Scheduled Scan". If you select the properties you will see a settings tab. In the settings tab you will see a power management box. You should check: "wake the computer to run the task" and "stop this task if battery mode begins"

Restart the computer gets it running ?? fwiw; I had that problem happening frequently. On my win8.1 - it was a recent new version 7 of EaseUs Todo back up program was the cause. I finally uninstalled easeus. Havent had windows defender freeze since. Which is what MSE is called on win8 . Experiment with pausing ease us ? or if you don't have that, program, maybe try uninstalling MSE and after a restart, re-install it. MSE has a timer on it,, if it stops, its supposed to try to restart in 60 seconds, maybe after 3 tries it gives up until you restart the computer.