Monitor not working - Signal not found

[Hadcat]

Monitor says HDMI Inactive, as well as Input Signal not Found.

I have swapped HDMIs and still doesn't work. The monitor works when plugged into PS but not PC.

I have read saying about extending display etc however, I cannot understand how to do thar, when the monitor doesn't show anything.

Also comments about graphics card etc and I don't know what this means.

[Prométhée]

Hello

[start]This is an automatic response
in order to avoid writing the same thing each time

Some elements may therefore not apply to you 
To be able to answer you effectively, we need some information

we need the exact model of your computer, and the product number
To find it follow this
for a desktop computer

HP Desktop PCs - How Do I Find My Model Number or Product Number? | HP® Customer Support
and for a laptop
HP Notebook PCs - How Do I Find My Product Name or Number? | HP® Customer Support

Give the full name with the product number P / N

this is not a model:
HP Desktop M01-F1xxx
the requested product number must look like this
Product Number: 9EE50AA # ABA
the model corresponding to this number will therefore be
HP Desktop - M01-F1033wb

Give the full version of windows

for windows 10 type winver in the search box
if you give the best information
your problem could have a solution more quickly (depending on the difficulty, of course)
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