[Yo-Yo]

My guess would be a new power supply.

[discostu]

How many beeps? It is actually a not so secret code:
http://www.computerhope.com/beep.htm

[ConservativeMind]

The backup battery for the BIOS settings probably needs to be replaced.

Get the manuals for the computer online, if possible, to help find this (location and type).

[Hang'emAll]

A bad video card/ card connection use to cause stuff like that.

Because of some interlock thing.

[LakeEffectLad]

Sounds like the CMOS battery is kaput.....

[gundog]

In before “Are you logged in?”

[woodenickel]

Remove and reinstall the ram

[Daffynition]

[Fhios]

Keyboard, monitor, video card, memory.

Make sure somebody didn’t ‘borrow’ anything.

[RightInTheMain]

On board battery most likely.

[bamagirl1944]

Your CMOS battery probably died. That is where the system info is stored. You might pull that battery out and put in a new one. It is usually a flat 2013 battery if I remember correctly. That would be the cheapest thing and first thing I would try.

[DeFault User]

My bet is on the battery as well. Cheap fix.

[Fresh Wind]

Unplug and replace every cable connector in the computer

[Enlightened1]

Battery....

Time to get a new computer. You can get one for Christmas.

[Organic Panic]

Try a new battery. But usually it will boot up regardless. Hit the F1 key when it starts beeping. Make sure all the PCI cards are in and boot it back up.

[Ingtar]

My guess is the bios battery has died.

[smokingfrog]

Make sure the keyboard is good.

[Covenantor]

You said it sat severalbyears unused. · As others mentioned, first thing to look at is Motherboard battery. · Check vents to power supply, might be a condo for vermin and dust. · Get rid of accumulated dust inside the box. · Get some of this. Get the real thing not some inferior Chinese product.

[Attention Surplus Disorder]

I also say the battery is by far the most likely culprit.

Try a new one for a cheap shot at fixing it. You recovered your data, that’s excellent. You’ll know quickly whether the batt does it, you’ll boot to “safe mode” and see if you can get by the beeps.

The last computer I bought was a used hp with WDOs 7 (which I like) for a whopping $125 CPU, kbd, mouse. I am assuming you are talking about a desktop, not a laptop, I could be mistaken. Desk machines are cheap now, everybody wants a tablet or some other whizbang. That was 3 years ago, it works fine, had to jam more memory in it. I liked XP Pro a lot, but.....it’s time. If you go to WDOs 7 or higher, don’t scrimp on memory, those machines need 8 GB or you’ll hate it.

[mmichaels1970]

I would guess you could still boot even if the CMOS battery has died. But you might want to try replacing it. It's just a "watch" battery located on the motherboard. Usually a CR2025.

The beeps usually indicate a RAM issue. Although sometimes the POST (Power On Self Test) have different beep codes that you can look up at the motherboard manufacturer site.

I would try removing all RAM sticks if you have more than one and then just install one of them.

You mentioned that you haven't used the computer for years but that you need some important data off of it. In the worst case, you can purchase a USB drive adapter at best buy (I use this.) Then you could remove the hard drive from the old computer, connect it via usb to a newer computer and copy the data off of it.