Not a problem I have had before. When booting up, I get two short beeps and the computer asks I either check RAM F5 (did full tests and all tests come up fine), continue with F1 or do F12 for set up. I have tried all and am unable to find anything wrong.

The two beeps started about three weeks ago. Just before the two short beeps started happening upon boot up, I was getting one long beep for about a month prior.

A week ago, I was unable to get it to boot at all and ended up reinstalling the OS, which worked fine for a few days when it started with the two beeps again. Now we are back to the computer asking I either check RAM F5, continue with F1 or do F12 for set up before it fully boots. Hitting F1 booted it up fine...or so it seems until I shut down and have to turn it back on again.

I have reseated the RAM, checked for tight fits on all hard ware. Replaced the video card 6 months ago. Fan works strong and I made sure it was dust free. Did discover the sata cable for the hard drive was bad and replaced when I did the reinstall of the OS. Computer is not quite two years old. XPS 420 Dell with Vista 32 bit and up to date on all updates. Any suggestions?

Looks like:

a) RAM timings are wrong (maybe RAM or CPU is overclocked?)
b) PSU isn't producing enough juice (check voltages in BIOS)
c) RAM needs replacing (try one stick at the time, or different slots)
d) BIOS needs updating (only if RAM is brand-new and not on the Dell's aprooved list)

Thank you! A couple questions:
a) How do I tell if it is overclocked and how do I check the timing?
b) What voltage should it be running at?
c) Bought new Dell RAM and replaced.
d) checked bios with Dell and it is what its supposed to be.

~~Mary

a) If you haven't tempered with FSB frequency and multipliers (and no one else did, including some performance-tuning utility) , then there is nothing you can do, except revert to defaults in BIOS.
b) The default voltage depends on RAM model. I suggest that you use some voltage-monitoring tool like HWMonitor. You can test-drive by running some 3D power-hungry game while HWMonitor is running. It will record low-points and high-points of your voltages. They shouldn't oscillate at all (unlike temperatures).
Consider this some sort of PSU test. If the voltages oscillate, then PSU's power capacity is definitely impaired.
c) If the RAM is checked, then the problem lies with some other component. Second in line is motherboard (followed by CPU and PSU).
d) (this one is exhausted)

Thanks Chalky! Will go try these!

You welcome.

(BTW, it's Chaky)