The power went out in our store And we tried to turn on our screen and it would not come on it started making beeping weird noises and then when the screen did turn on it says that it was an unsupported device push escape for start menu and you can push escape but it does nothing but the system automatically shuts down and you can’t do anything I need to get this back on
It is possible that there was a "power-surge" that damaged the computer.
You should contact HP Support, to get them, for a fee, to repair/replace the computer.
You will be without the computer for a week or two -- shipping to HP, repair, shipping from HP.
To continue your business, you need to purchase a new computer.
Do you have an I.T. department that can reinstall the POS (Point Of Sale) software?
Note that if you can purchase an identical model, you might be able to "transplant" the disk-drive (and its software) from the old computer to its replacement, to continue running the software, but on top of the new hardware.
P.S. You may wish to investigate purchasing a UPS (Uninterruptible Power Supply) to protect your "next" computer from any future power-surge. Less than $100, to buy this "protection". After a few years, the battery inside it may need to be replaced ($50 ???).
Be alert for scammers posting fake support phone numbers and/or email addresses on the community. If you think you have received a fake HP Support message, please report it to us by clicking on "Flag Post".