Power Button locked

[VickieJ3]

The Power Button is locked.  

[Williamjoe2442]

Step 1. Locate the menu button on your monitor. Depending on your exact monitor, the button may be clearly labeled, or...
Step 2. Ensure that nothing on the desk is pressed up against the menu button and holding it down. This is a common...
Step 3. Press and hold down the menu button for at least 10 seconds.

This may help,
Will Joe

[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)
Learn how to use the Community

Advice for asking the "Very Best Question"

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Although the proposed solution may work,

sometimes it will depend on the model...