Apparently Dell Vostro 1050 is a laptop.
The hard drive MUST be detected by the computer's bios Setup.
Are you SURE it's not being detected ?
If it's detected fine when it's connected to another computer, if it doesn't show up as being detected in your laptop's bios, your laptop is DAMAGED !
Have you, or is it possible anyone who has had physical access to your laptop has
- dropped it, or subjected it to a physical jolt ?
- spilled liquid on it, or exposed it to liquid such as rain, or sprayed it with liquid ?
- Has there been a power failure event, or has there been lightning strikes in your area, when the AC adapter was plugged into it, since the computer last worked correctly ?
NOTE that the bios not detecting a bootable hard drive partition is a DIFFERENT PROBLEM !
The hard drive must have an operating system installed on at least one of it's partitions in order for it to be found bootable.
A new hard drive has no data on it and it will NOT be found to be bootable.
If you're SURE it has an operating system installed on it....
Check the Boot Order or similar settings in the bios. If that is NOT correct for your situation, in some cases the bios WILL NOT find a a bootable hard drive partition !
Floppy drive or Removable drive or similar
CD-Rom drive or similar
Hard drive or similar
Network adapter or similar.
NOTE that in most cases, you DO NOT list Network adapter or similar BEFORE hard drive or similar, unless you are using a connection to a business or institutional network and you have a wired or wireless connection to that network connected to your computer.
When you DO have Network adapter or similar listed BEFORE hard drive, if you DO NOT have a wired or wireless connection to a network connected to your computer, the bios WILL NOT try to boot from the next thing in the boot order list - no bootable hard drive partition will be found.
Also, if your boot order is set to boot from a USB connected drive before the hard drive, if you have a flash drive plugged into a USB port, they are NOT bootable unless you have followed a procedure to prepare it to make it bootable, and for most if not all bioses, the bios WILL NOT try to boot from anything listed after that in the boot order list if the flash drive is not bootable. The cure for that is to unplug any flash drives you have plugged in before booting the computer, then change the boot order settings in the bios so the computer is not trying to boot from a USB connected drive.