Can You Use Someone Else's Backup And Restore It?

I dont know what kind of backup, cause you didnt specify, however i will assume its windows restore image.

please note that windows backup images are not the easiest to restore from, and i reckon you can restore it on another machine.

However if you want a truly generic backup, you have to use cloning.

i work at backup company so take my advice.

http://redobackup.org/

The above is the easiest cloning tool, basically it will boot in an non Windows environment and backup your windows parition or other paritions from a sector level, and not file system level, meaning it backup in method that does not give a shit about the filesystem in the hard drive / SSD, and its more basic and pure and close to HDD nature (sectors/blocks)

That backup, once done, can be produced and restored to any HDD and the HDD restored will have the same OS, and files as the original

I personally use ghost 4 linux for those situations

http://sourceforge.net/projects/g4l/

However its abit advanced so stick to the first link.
 
I think so because the Backup and Restore option does not include system files, per se, so it won't matter if both PC's are different to each other however, I suppose that is not what you are after so you may need a repair disk if you are trying to replair your OS. You could use his Vista OS install disk just to do a repair but not install.