If you are the only user then you are an administrator, but you will run as a standard user, hence the need to ok the UAC messages that pop up time to time. Did you upgrade your laptop from XP, if so the admin account will be there?
It's not really a good idea, but if you must open the Start menu and type cmd in the search box, then press Ctrl+Shift+Enter. OK any UAC prompt and in the box that opens type the following: net user administrator /active:yes
The admin account will then appear on the Welcome screen without a password, hence the not a good idea bit. Make sure you apply a password as soon as you can.