Cause a UAC popup from commandline without custom tools
Solution 1:
You can use the Start-Process cmdlet in Powershell with the RunAs verb. More here: http://technet.microsoft.com/en-us/library/dd347667.aspx
Solution 2:
Simply run the cmd.exe as administrator.
The keyboard shortcut for this is [shift] + [enter] after you have selected the commandline from the start menu. A UAC window should pop up.
OR
Run everything as Admin
Not recommended for everyday usage, but there is also a built in administrator account that you can activate in windows that will simply run any and all applications as root. In an administrative cmd:
net user administrator /active:yes
Change that to '/active:no' if you want to disable the account. A brief intro here.