Please Help: graphics card?

I have a Packard Bell 2.9 ghz Celeron D
at present running ati radeon 9250 agp graphics card.
will ati radeon HD2600 pro with DDR2 run on my system with my ram
@ DDR 1, have 1.250gig of ddr ram.
many thanks if you can help with this.

You of course will need a card with an AGP interface.
Then you will need a power supply of 400W or better according to ATI.
ATI has a certified PS list at their site.

If you are going to purchase a PS, I recommend posting your prospects in the Hardware section of the forums and let the members here comment on your choice(s) prior to purchase.

I concur you will need a upgrade in PS if you going to use higher end AGP card. But make sure it is 4x or 8x AGP as well for the slot. You can use 8x in 4x but best if 4x to 4x and 8x to 8x. The reason for upgrade PS is higher end card requires a PS connection beside the AGP connection. So be sure to check that part out as well before buying.

HD2600 pro will work but as stated prior you will probably need a new PSU. As low as a 300w should be more than sufficient. Also your current Motherboard is most likely AGP 4x so you won't get full capability out of your card. But this I don't know. DDR2 will not work with a DDR1 motherboard. Godd Luck!

coolcolors makes a good point about AGP slot versions.
When I saw "CeleronD", I assumed AGP 8x but that may not be.
Verify what AGP standard (version) your motherboard is compliant with.
If you can't determine, post your computer brand and exact model number.

AGP info : (notice how the cards are keyed)
http://en.wikipedia.org/wiki/Accelerated_Graphics_Port