Unable to activate system restore, on screen message "system restore encountered
an error trying to enable/disable one or more drives. Please restart your computer and try again"  I have tried restart several times no joy, please help

Try running checkdisk on your hard drive(s) and see if it clears up the problem.
Open My Computer, right click on a hard drive and select properties. On the tools tab, select error checking, check now. Check both options and click start.
The dialog will then say it can't check the disk without full control. When it asks if you want to schedule a check on the next reboot select yes.
Check disk will run as soon as you reboot your computer and will correct any file system errors.