I have just spend more than one hour to get my system usable again after Prevx (paid version) started to crash out of the blue continuously and would not stop. Windows 7 x64 here. It all started a few weeks ago with frequent entries (multiple times a day) in windows event log indicating that the CSI module stopped unexpectedly. Sometimes, the entry was accompanied by a second message: Reading this forum set my mind at ease somewhat, as I learned that this behavior was "normal". Well, ok. The next weird issue was when I tried today to scan an entire external hard drive, a message box popped up (no screenshot unfortunately) that just gave me the insightful error message... ...plus an "OK" button. Beautiful. A few hours later, trying to use the scanner produced the following crash message: http://yfrog.com/2sprevxj Plus, I started seeing this in my event viewer: At that point, I tried to repair/reinstall Prevx, but after clicking on the uninstaller, the same message would pop up, and now would keep popping up every few seconds. Every. Few. Seconds. I rebooted, but immediately when the service started, this message started to pop up every few seconds. I had some work to do tonight, brilliant. I fired up sysinternals autoruns and unchecked all the boxes for prevx drivers and services that I could find, and rebooted. At that point, my keyboard was dead. I could not even log into Windows. Rebooted again, this time into safe mode. Same problem. Rebooted again, and booted with the "last known good configuration" option. This worked, I could get into windows again, but the Prevx error message would pop up again every few seconds. Needless to say that my desperate attempts to delete prevx.exe or other related files did not work as they were locked. At that point I booted into a separate Windows install from an eSata HD and deleted every file related to Prevx I could find on my main install, as well as doing a manual search/delete in my main install's registry remotely from my good Windows install. It took some time... That brought back the computer. I then reinstalled Prevx and immediately uninstalled it again, and executed the removal tool, to remove all traces I might have missed. Even after that I found leftover entries in my registry for various Prevx services that were not removed automatically. Looking at my Windows event logs showed that in the 60 minutes I struggled with the recovery of my PC there were 1669 (!) new event messages, including many errors, in the logs. Many of them were related to prevx, but others were seemingly random messages about other services and windows components failing. Horrible... Gentlemen, I am seriously unimpressed. I believe the concept of Prevx is superior to signature based products, I bought the full version, and I really really want to like the product. But - this was the by far worst experience I ever had in my 20+ years of PC usage in regards to anti-malware (or malware, for that matter). Never ever has (anti-)malware managed to compromise my system so deeply that I had to jump through hoops to get it working again. I hope this does not come across as a mere rant - I sincerely hope Prevx continues to refine the product, and will watch it's evolution - but after this experience I will likely file this under "experimental software", take a seat on the fence and buy something more prime time ready. PS: No, I did not catch a malware infection which would then cause this. I have scanned the repaired install from 1) Linux Bootdisk with Avira Antivir 2) From a separate, offline Windows box with GDATA Antivirus, MBAM and HitmanPro. Zero results.