Msstart.exe is an adware program Adware.Satbo. Msstart.exe downloads and displays advertisements. Related files: %System%\Svrhost.exe %System%\Msstart.exe Setupad.exe Adds the value: "svrhost" = "%System%\Svrhost.exe" "msstart" = "%System%\Msstart.exe" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Kill Msstart.exe process and remove Msstart.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.