help vista updates and now stuck in dos

my parents computer was stuck in the loop of 3 of 3 for windows updates. it would not even let us start it in safe mode (even in safe mode it would go right to the loop) I have no idea how but somehow they are now at a full screen C promt in dos. they do not have a disk for vista (the disk did not come with the computer when they bought it new form Radio Shack about 1 1\2 years ago)
does anyone know how I can get them back up? they are in NC and I am in TX so I am doing this over the phone until I can get it to a windows screen and can remote in

https://discussions.virtualdr.com/im.../2012/04/5.png

They can download a Vista Recovery Disc here:

Vista Recovery Disk download

Once that is done, boot up with it, and run Startup Repair.

How to automatically repair Windows Vista using Startup Repair