Try this: PsExec with the -s parameter. And -i for interactive window. To launch a new cmd.exe from an elevated command prompt. Then verify with the whoami command.
My Computer
At a glance
Windows 7 Pro 32Intel(R) Core(TM) i5 CPU M 540 @ 2.53GHz4,00 GB (Usable 2,98)NVIDIA NVS 5100M
Computer type
Laptop
Computer Manufacturer/Model Number
HP Elitebook 8540p
OS
Windows 7 Pro 32
CPU
Intel(R) Core(TM) i5 CPU M 540 @ 2.53GHz
Motherboard
Hewlett-Packard 1521
Memory
4,00 GB (Usable 2,98)
Graphics Card(s)
NVIDIA NVS 5100M
Sound Card
NVIDIA High Definition Audio
Screen Resolution
1600x900
Hard Drives
INTEL SSDSA2CW120G3
Antivirus
F-Secure Internet Security
Browser
IE, Firefox, Opera
Other Info
Sandboxie,
SRP (Software Restriction Policy),
EMET (Enhanced Mitigation Experience Toolkit),
WFC (Windows Firewall Control by BiniSoft),
Malwarebytes Premium