direct sector by sector scan File Scavenger
you can trial it (but rescue is limited) $40 (not that expensive)
for repair of partition tables Disk Patch also $40
its generally recommended you rescue first then attempt repairs
I find it unlikely he deleted his system partition but in the event that was done from outside of windows somehow fixmbr
note > If an invalid or nonstandard partition table signature is detected, you will be prompted whether you want to continue. If you are not having problems accessing your drives, you should not continue. Writing a new master boot record to your system partition could damage your partition tables and cause your partitions to become inaccessible.