Accidentaly deleted Environment variables

"I deleted Environment variables in Vista" wrote:

I deleted environmental variable from advanced settings in system menu, how
can i fix this? i can't enter to the advanced system menu again because the
windir variable was deleted.
in Windows Vista
Thanks

Ok i solve this. I´ve enter in safe mode (pressF8 at start up) and recovery
the system in a point (date) before i deleted this variables.
Bye