No boot drive

[Mafia67]

Had a power outage and computer was on and since then it won't boot up. It says can't boot up, no operating system found and won't let me put a new operating system on it

[Elohi_NR]

Hi @Mafia67,

Welcome to the HP Support Community. 

I'd like to help!

Perform the hard drive symptom test in HP PC Hardware Diagnostics UEFI

• When Windows won't start, use the following instructions to open the Symptom Tests menu, and then run the hard drive test.
• Hold the power button for at least five seconds to turn off the computer.
• Turn on the computer and immediately press esc repeatedly, about once every second. When the menu is displayed, press the f2 key.
• On the main menu, click Symptom Tests.
• The Symptom Tests menu is displayed.
• Your Symptom Tests menu might be different, depending on the components installed on your computer.
• Select Hard disk/SSD drive issue, and then press enter.
• If the computer has more than one hard drive, select the drive to test. To test all the hard drives, select Test All Hard Drives.
• NOTE:
• If the test does not find a hard drive, try reinstalling Windows using the steps in Reinstall Windows on the hard drive.
• When the test is complete, the screen displays the results. Test results are also available in the Test Logs on the main menu.
• If the hard drive passes the Quick Test, but there is still a problem with the hard drive, run the Extensive Test. This test includes the SMART Check, Short DST, Optimized DST, and Long DST. To run these tests individually, select them from the Hard Drive Tests menu.
• If the hard drive fails a test, click Troubleshoot.
• Follow the on-screen instructions to attempt to resolve the problem, and then click Yes.
• If the problem is not resolved, click Yes to contact HP Customer Support.
• Write down or copy the failure ID (24-digit code) and product ID for when you contact HP Customer Support. You can also use your mobile device to take a photo of this information or to scan the displayed QR code. The information is also available in Test Logs on the main menu.
• If your computer is online, click NEXT to go to the HP Customer Support website.
• If your computer is offline, use your mobile device to scan the provided QR Code and access HP Customer Support.

Click here for further assistance. 

If this does not help, then this might need service. 

Hope this helps! Keep me posted for further assistance.
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