how do i do a system restore from dos without discs or being able to mark the hard drive as last known ...Not sure what it is you are attempting...
I am sure however more info is needed.I am trying to reformatt a computer but i DONT have any discs, the computer has a VIRUS so I wanted to know a dos comand that will do a system restore (bring computert back to the way it was when bought) I need to be sure windows vista will be intact. the comand i do have is rstrui.exe but that needs a last known something on hard drive , the computer was never BACKED up. HELP!1st of all you are confusing 2 different functions...
System Restore is built into Windows and only affects System files...nothing more.

So in the case of a nasty infection this feature will do little or no good.

A Factory Restore is what you are referring to and to do so you need the CD's that shipped with the machine...no DOS COMMAND will do this.

The only exception here is if it's a laptop and/or it shipped with a hidden restore partition....if not you will need Windows CD's to do this.ok soooo to do a system restore hoping it will help cant hurt can i do this through dos?You don't have DOS...you have a Command Prompt...

Try Here...As patio said, system restore WILL NOT cure any infection.