Pema

I decided to give it one more try and to follow the advice to download and run mbam-clean.exe, restart and then do a clean install of a newly downloaded installation exe. and now my new installation is working! So thank you for these suggestions and I'm glad my setup is working. BUT for the casual, non techie Malwarebytes user, who only is familiar with the automatic updates and won't go to some tech forums, this must be a major headache! I'm wondering what glitch and what left over files this mbam-clean.exe is taking care of?

Just to clarify, I have been running this combination of Microsoft Security Essentials, Comodo Firewall plus and an installation of Malwarebytes free which I use for regular manual scans without any problems for years now. Today, during the update process as well as during the clean install which I did as a second attempt, Comodo Firewall with Defense Plus did not post any partially limited or fully limited unrecognized files or processes. This is what Comodo Firewall would display in case there were any issues, therefore I really think that these latest update problems do not lie in the area of some compatibiliy problems with one or another firewall or a specific antivirus application. I did not look for reports about update issues on windows vista or windows 7 systems -- maybe this latest update does not work with XP3...? The previous version 1.51.2.1300 was working flawlessly and since I kept that setup exe, I might install it again until a new working update becomes available. Thank you for all your work in finding a solution and good luck.

Similar problem for me with the update to the new 1.60.0.1800 version. BUT I am running XP Pro SP3 with Microsoft Security Essentials and Comodo Firewall with Defense Plus. After the update Malwarebytes free can not start but gives error messages. I uninstalled using RevoUninstaller and rebooted and ran Ccleaner and cleaned out some remaining registry entries. Then I downloaded the new latest version 1.60.0.1800 and did a clean install. But even after this clean install the same problem occurred with the program not starting up and giving some error message. So it is not ZoneAlarm or Avast that's causing these problems but this latest version of Malwarebytes which is faulty. I uninstalled the program and I'll watch for a fixed version before installing again. Please don't just look for some compatibility issue with ZomeAlarm or Avast the problem lies clearly within this latest version of Malwarebytes. I hope this info helps in resolving this issue.