Hello,
I am looking at one of my friends computers and he said it just stop working one day. It is a Dell Dimension E520. The only specs I can REALLY give you are that it is running windows vista home premium. When you press the power buttonon the front of the computer it makes a series of beeps. It goes BEEP BEEP....BEEP BEEP BEEP.......BEEP. Thats it. I can hear the fan running and i took off the cover and tried clearing the CMOS because i have done that in the past to reset motherboard and found that does the trick. I have tried to hit F2 to get to the BIOS but nothing even comes on the monitor EVER.  I checked monitor on my laptop and it works fine. Any suggestions guys? Did you try to re-seat RAM, video card (if any)?no, I will take out ram and put it in different slots, i think it has an integrated vide card on the motherboard. Thanks broni. Will get back on that after I try and seee what happens.Sure thing The RAM trick worked. It worked in the black slots but not either of the white slots they used to be in. Weird. YOU ARE AWESOME BRONI. Now to remove all the Malware. I'll hit up EVIL when I ge the time to go back over there. THANKS AGAIN!  Nice job  :)My beeping problem solved. I had trouble with my computer today. It is a Dell Inspiron 530 desktop. it is about 5 or more years old. It would started but would not boot up and just kept beeping like an alarm. I went on the net to find an answer but I don't KNOW much about the inside of a computer. I took the side panel off and the front panel where the USB ports are and the on and off button.  It was so full of dust you could not believe it. I vacuumed the front with a small portable vacuum to get the dust out, there was a lot of dust near the on and off SWITCH. I checked for loose WIRES and did not see any. I plugged the computer in another outlet that did not work. Then a miracle. I turned the computer on it's side. I used a small duster with a 2 inch long brush and kind of dusted over everything that I saw that need cleaning, like the fans and whatever. I was too afraid to touch anything or do the wrong thing. I then turned the computer right side up, turned it on and no more beeping. Now it connects to the internet faster too. The post is 4 years old...but glad it worked for you...
However in future i would discourage using any kind of vacuum in a PC as it generates enuff static electricity to fry valuable components...