you cannot recover an operating system from a winmdows (OLD) folder this will contain your files from your previous OS but is only of use to recover vital files ,its not complete enough to recreate you old installation .
1 does your PC/LAPTOP have a recovery system (hidden partition ,and recovery disc .
2 set the bios to (boot from cd ) and rerun the disc ,in the process select recovery .
3 you could try to install vista ,exact same version from disc . if enough of your old install is present you may have a restore option come up .