Hi and welcome to the forums
My advice to you would be very carful when fiddling around with the registry, use your common sense and make backups before you change anything.
To fix this registry error I would recommend using a program such as CCleaner
which allows you to check for and fix registry errors and take backups of the registry as well (but system restore points are much more useful in many situations than the backup file CCleaner creates.)
Use CCleaner with caution and don't make checking the registry for errors using it a regular habit (once or twice a year if you don't have problems) because it can cause more problems than it solves.
Post back with any results.
If you have any questions please feel free to ask away.