Can't get OS WIN7 to reinstall on a Inspiron 1750

Hi All

Bought an Inspr_1750 for what I though was a good price $150 Only to get it home and find the OS partition was wiped clean, the recovery part and the diag partition are still there but not accessible tried many ways  to reinstall win7 but no such luck feel it has something to do with the remaining partitions not sure.Wonder weather to sent to Dell for factory reinstall with all the bells and whistles  or reformat whole hdd and be happy with a reasonable laptop service tag # is <ADMIN NOTE: Service tag removed as per privacy policy>the floor is open Thanks Bou Bou