XPS 8300, missing operating system

Which version of Windows are you running? It sounds like Windows is corrupt and needs to be repaired. If Windows Boot Manager is in the list of options when you press F12, try that for your first boot option.

The following may help..

https://www.dell.com/community/Desktops-General-Read-Only/Missing-operating-system-on-XPS-8300/td-p/4579518

https://www.dell.com/community/Desktops-General-Read-Only/No-Operating-System-Found/td-p/5139681

thanks for your reply. I believe the system came with windows 7 and I updated it to 10 a couple years ago. I tried the 1st link via the SATA and RAID process and I got a message that said "reboot and select proper boot device or insert boot media in selected boot device and press a key" I tried going back to the hard disk reboot option and ended up with the "missiong operating system missing" message. not sure what I did but also got to a screen that said Intel rapid storage technology option ROM...and under the raid volume's heading there was a line that said ARRAYO and it said status failed. I then tried the second link but the link to me to a dell page with items for sell. I also tried another option within this link and it pointed me to using F8 but it did not work? other suggestions? should dell give me disc with the operating system on it or is there another way for me to get it?

Firstly attempt Data Recovery onto an external hard drive using a Bootable Linux USB: https://dellwindowsreinstallationguide.com/data-recovery-using-fedora-2/ Next Download Windows 10 Installation Media from Microsoft, make a Bootable USB for a Legacy BIOS and Clean Install: https://dellwindowsreinstallationguide.com/windows-10/ Note before Clean Installing you may want to upgrade your Hard Drive to a 2.5" Solid State Drive as this will give you a considerable boost in system performance. This system has 3 Bays, I used to have 2×1 TB HDDs and a 500 GB SSD in my XPS 8300.

Get a new hard drive and clean install windows 10.

https://www.amazon.com/WD-Blue-2TB-Hard-Drive/dp/B013QFRS2S/

 

https://www.amazon.com/Enclosure-External-Support-Windows-Included/dp/B004K4TE5O/

 

Before going too far, I'd suggest you try clearing BIOS:

1. Reboot and immediately press F2 to open BIOS setup, assuming you can...
2. Copy down all current BIOS settings
3. Power off, unplug
4. Press/hold power button for ~15 sec
5. Open case and remove motherboard battery (check Service Manual for details)
6. Press/hold power button for ~30 sec
7. Reinstall the battery (Time for a fresh CR2032 3-volt coin cell battery?)
8. Close up and connect only mouse, monitor and keyboard
9. Reboot

If that doesn't help, then consider the other suggested posted above...

Given the age of the system hard drive has physically failed.

Time to install new hard drive and clean install.

There are no soft recovery for physically bad hard drives.