Dell Inspiron - Restore to factory settings

Hello,

I have been reading posts which are similar and have followed the F8 instructions multiple times but for some reason I am not getting the option "Dell Factory Recovery" option. When I click "Repair your computer" it takes me to another screen that tells me "failed because a required device is inaccessible." I have done it in the past with no problem but his time was the first time I got the error. Any Ideas? Thanks so much for your time.