Invalid System Disk error in laptop

Hi,
I have a HP Laptop at my home which is quite an old one. Recently when I tried to turn on the laptop I have noticed a message which says, Invalid system disk. Upon receiving this message I have tried to enter into safe mode where it didn’t work. The computer is not letting me inside. Since this is an old laptop there is no support available for this one. So I am here looking out for some help from you guys. Will be thankful for your time.
