You can see which edition of Vista you have by right clicking on the Computer
button in the Start menu, then click Properties
Not sure why you would not be seeing it, if you are running the Windows Aero
color scheme. Did you see if restarting the computer helps any?
You can see if doing a System Restore using a restore point dated before the problem started will fix
System Restore - How to
Try a Repair install. This will allow you to repair your Vista installation and keep your user account files, settings, and programs.
Repair Install For Vista