Hardware Not Detected?

[XKwisite]

I was just wondering if you guys could help me out with a problem. Here it is,recently i added a gig of ram(same as the original ram)to my computer aswell as a new hard drive and disk drive and my computer isn't detecting any of them. I know they should all be compatible because they came from another computer of the exact same model. Also the disk drive will come out and such put the computer doesn't recognize it. I've tried "Detecting new hardware" with the device manager and all that but it still isn't finding any of that. Could anyone help?

Computer: Dell Dimension E420
OS:Vista home premium

[Xente]

try reinstalling the hardware, sometimes one little thing comes loose and then it wont detect it at all

[Shattered Skies]

Also try installing the hardware one piece at a time.

[TheJESTERJ]

Also try installing the hardware one piece at a time.

Yeah, use this method to determine if one piece is conflicting with the others. Are you sure the RAM is the same? Does this current motherboard support the RAM type?

[XKwisite]

Yeah, use this method to determine if one piece is conflicting with the others. Are you sure the RAM is the same? Does this current motherboard support the RAM type?

I think it does since both sticks came from a dell dimension E520

[Espio0]

the thing with those brand computers is that only specific types work, the types you mus buy from them

thats why its best to pik your own pieces and let someone build it

almost every brand forces you to buy expensive upgrades for those computers

and they give you a real hard time with the waranty if you change something

ah well, DELL : HELL