Hp desktop alarming when turned on - HP Hewlett Packard Pavilion Slimline S3100N PC Desktop

If you unplug the power cord from the wall and the PSU, then flick the little red voltage switch on the back up and then back down again, plug it back in and it should work again

hi t could be that your CPU fan is loose or that your RAM(memory) came loose try looking on youtube to see how to put RAM (memory) into pc and make sure your CPU fan is secure....bonnell

Check "wake on..." settings in the system BIOS, likely that "wake on lan" or
"wake on ring" is enabled.

So disable it and your problem is gone !

Business PC's can trigger an alarm when the cover is removed to prevent unauthorized access to the hardware.

The following link should should you how to reset the alarm.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=110&prodSeriesId=3264501&prodTypeId=12454&prodSeriesId=3264501&objectID=c00789832

It sounds like one of your memory cards are either loose or bad.

Your MOBO is fry.

Go to start, run, enter msconfig, and at the startup tab, uncheck the zone alarm program. Restart your computer.

Check CPU and memory seated correctly, may have overheated so check fans working and heatsink clean of dust etc.
The led should flash an error code. The number of flashes says what is wrong. There are some 9 codes, from bad to disasterous!
see
http://www.dectrader.com/docs/set1/emr_na-c00278580-1.pdf

Press
Start-settings-profiles-normal(or profile wich you want to change)-press menu on the profile-then choose edit.
And there you will find -
Ring volume
Alarm volume and others.

The intermittent beeping is the error code. It is important that you notice how many beeps your computer makes.
Then, you can go to the following link (from HP) http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph07107&lc=en&cc=us&dlc=en&product=71010&lang=en
and check what is wrong with your computer.

Anyway, you can always recover the information on your computer, but will have to take the hard disk out of the computer and plug it onto another as a secondary hard disk.