Invalid signature detected, red screen. How do I fix

[Lynstan]

Hi, granddaughter has done something to her all in one hp model 22-b000na. When switch on it come up with red screen saying invalid signature detected, then blue screen saying, boot device not found. Tried pressing window key and B key switching on power button, nothing happens. Ran system diagnostics, passed. Help

[Lil_Boy_Blue]

Hi
Make, Model and OS please.
SKU: if possible
System SKU: N6K07EA#ABU
Please do not post Serial Numbers.

Boot Device may be a missing OS or misconfigured BIOS since the hardware tests passed.

https://support.hp.com/us-en/product/hp-22-b000-all-in-one-desktop-pc-series/10734597/model/11875098

https://support.hp.com/us-en/drivers/selfservice/hp-22-b000-all-in-one-desktop-pc-series/10734597/mo...

Create Windows 10 installation media

To get started, you will first need to have a license to install Windows 10. You can then download and run the media creation tool. For more information on how to use the tool, see the instructions below.

Download tool now

https://support.hp.com/us-en/document/c02693833

Turn off the computer, and then connect the power cord.
Press and hold the Windows key and the B key at the same time, and then press and hold the power button for 2 to 3 seconds.
Release the Power button but continue pressing the Windows and B keys. You might hear a series of beeps.
The HP BIOS Update screen displays and the recovery begins automatically. Follow any on-screen prompts to continue the startup to complete the recovery.
HP BIOS Update recovery in progress

If the HP BIOS Update screen does not display, repeat the previous steps but press the Windows key and the V key. If the screen still does not display, your computer might not support the feature or there is a hard drive issue. Continue to the next step to install a BIOS recovery file from the HP website.
If the Power light turns off, the Power button was held too long. Repeat the previous steps, making sure to hold the button for only 2 to 3 seconds.

If in doubt please ask.

[Lynstan]

Hi, thank you for taking the time to help.  Did try the window key and b key, nothing happened. What I did manage but might not be correct???? Hit F10 key, set to factory default, computer came on as it would normally.............switched it off and then went back and the ruddy red screen came back????? Does this mean anything?

[Lil_Boy_Blue]

Hi

Nice  "ruddy and red" combination.

So try the F2 Hardware Test.

IF it boots/loads again have a USB stick plugged in and make this, it is crucial...

https://www.microsoft.com/en-us/software-download/windows10

Create Windows 10 installation media

To get started, you will first need to have a license to install Windows 10. You can then download and run the media creation tool. For more information on how to use the tool, see the instructions below.

Download tool now

Then try and run some corrective software....

C:\>sfc /scannow

Beginning system scan. This process will take some time.

[Lynstan]

Hi, me again. Managed to get back into computer with F10 key. Default setting, then went looking for windows updates.  Computer took hours to update. Had to do it twice as poor machine could not cope. You would not believe that my daughter has a degree in multi media and web design?????? Problem is she can’t get her fingers off her mobile phone😂😂 Anyway did the restart , fingers crossed. It restarted 😃. So restarted again and started. So hopefully fixed. Will switch off , later, need wine first just encase ruddy red screen appears......will update tomorrow. Thank you again

[Lil_Boy_Blue]

Hi

Fine.

BUT you still need a UB stick with Windows 10 on it for the day you can't cross your fingers and wait.

While red wine seems to be a panacea for everything, it doesn't really work with computers and cars.