Very true. If you go into a command prompt and type "net stop themes" - you must be running prompt as an administrator to get this to work.
This will only work for your current session. If you want to permantely disable the themes service go into services.msc > find the themes service > select start-up type "disabled".
My Computer
At a glance
Windows 7 Ultimate x64 RTMCore 2 Duo 2.8 GHz4GBQuadro FX 2700M
Step 1. Right click empty part on the desktop and choose “Personalize” from the menu.
Step 2. Then you can simply scroll the themes down until you see the Basic themes. Choose the basic theme that you want to use, and press “Save changes.” button at the bottom.
Step 3. Hence, Aero theme will be removed and your computer will also perform better.