Hello noknojon Thank you for your reply. I have "Microsoft Security Essentials" and the Windows Firewall, on Windows 7 x64. Since I have this computer, I use this setup and I had no problem before. These problem is present since the last software update of MBAM. My system is not infected. For the first and the second message : I have uninstall/reinstall MBAM without success. So I have downloaded the DLL and register these (by regsvr32). I have also download and instal the "VB SP6" on microsoft.com Further to it, the third message is appeared. After searching on Google I have then download "mbam-clean.exe". After reboot the system, I have reinstall the last version of MBAM and the last message box is appeared. Thank you for your help. Juju.