Windows Vista safest operating system from Windows

Why the windows vista is the safest operating system till now from Windows ?The reason for the above question is that the User Account Contro (UAC) feature included in windows vista. User Account Control (UAC) is a new security component in Windows Vista. UAC enables users to perform common tasks as non-administrators, called standard users in Windows Vista, and as administrators without having to switch users, log off, or use Run As. A standard user account is synonymous with a user account in Windows XP. User accounts that are members of the local Administrators group will run most applications as a standard user. By separating user and administrator functions while enabling productivity, UAC is an important enhancement for Windows Vista.But the problem is , For security whenever you need to configure Vista settings, you need elevated privileges - even if you are logged on as the administrator. Before you can complete an administrative task, the User Account Control manager pops-up with a 'Continue' message.If you feel a little guilty in turning off UAC because ,a) people want to get rid of the irritating 'Continue' pop-up message box.b) Feel shamefaced at disabling this Vista security feature.but my Own advice is that you please dont disable is unless and until it is needed. and if you need to disable it temporarily then enable it afterwords.