Optiplex 280 Booting problems

I have an old optiplex 280x that i just installed 4 gigs of ram in.
Now, Instead of the regular "Press f1 to advance" or something like that i get
Intel in colorful letters in the top right corner and a bunch of writing with "DECOMPOLATION OR DISSASSEMBLY PROHIBITED" Without any options, And to shut down my computer, i have to remove the power cord.

I also changed my hard drive because i thought my old one was blown. And a peculier thing about the computer is that it only has 1 of the grey suppy cables.( Not The power cables, The Ones that connect to an HDD) but it has 2 "Exits" and im not sure if i can hook up both my hard drive and CD rom both to the same cord. And i think thats also causing a problem.

Thanks for any help!

(Edit: i was getting the 1-3-2 beep code but i just moved ram positions.

 

IDE cable
http://www.wpclipart.com/computer/hardware/cables/ide_cable.png.html
can support a hard drive and an optical drive.

 

Okay, But that still doesnt solve my problem of the computer not getting past the first screen Any help?

 

Try starting it with no RAM.
Then going in and adding one stick of RAM at a time. Boot up. If OK then add another stick of RAM and boot up... continue and see if it is one RAM module that is causing the message.

A quick look around the net seems to point to a RAM problem. You might first check that all your modules are firmly seated before starting over and going stick by stick.

 

Perhaps it Could Be the Cpu or motherboard is blown? Because i have The "Stock" intel motherboard. Ill look into getting a new Cpu.

 

If the error only occurred after changing the RAM go back to that. Take out the new RAM and go back to what was in there before. Or try no RAM and add one stick at a time to see if possibly a stick is bad or not seated properly.

 

The Problem didnt occur when i changed the ram, I stopped using my computer, bought a hard drive and video card , and comp. didnt work. I tried installing the video card once and it didnt even work then.

 

You are not getting anything but this error. Not even a BIOS screen try going back to basics.

Unplug the PC and remove the CMOS battery (small quarter-sized coin shaped battery) for about 3 minutes. Put the battery back, plug in, reboot and see if you get the DELL screen.

 

okay now im back to the initial no boot device available and i've the hard drive hooked up but it doesnt detect it any ideas? (the ide cables and power supply cables are all hooked up) ive double checked all the connections but still no luck. Any help would be appreciated !

 

Try just the HD on the end connector of the IDE cable. Leave the CDROM off the cable for now.

Double check that the jumper on the HD is set to MASTER according to the diagram on the label of the HD. If there is no diagram post the make/model of the HD. (It is best to set the jumper to Master or Slave rather than Cable Select for troubleshooting.)

And, just to be sure are you working with a HD that has Windows installed? Because an empty HD will show as no boot device.