Please read this installation guide carefully if you are using Vista/W7 and have User Account Control enabled

No doubt this is one of the most common questions/frustrations about Windows Vista/W7.
Even if you log on as an administrator, you don’t really have administrative rights, thanks to UAC (User Account Control). But since setups require administrator rights this behavior could cause problems.

When you run a setup program, right-click the setup program, and then click Run As Administrator. Then, it will really run as an administrator.

What is User Account Control?

User Account Control (UAC) is a new security component in Windows Vista/W7.
UAC enables users to perform common tasks as non-administrators, called standard users in Windows Vista/W7, 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.
To help prevent malicious software from silently installing and causing computer-wide infection, Microsoft developed the UAC feature.

Unlike previous versions of Windows, when an administrator logs on to a computer running Windows Vista, the user’s full administrator access token is split into two access tokens: a full administrator access token and a standard user access token.

During the logon process, authorization and access control components that identify an administrator are removed, resulting in a standard user access token. The standard user access token is then used to start the desktop, the Explorer.exe process.

Because all applications inherit their access control data from the initial launch of the desktop, they all run as a standard user as well.