Can memory be mixed?

[pd123]

I have a Dell 600sc with the 256 stick that came with it and a Kingston 512mb. Can a Crutial 512mb be mixed with the Dell 256mg and the Kingston 512mg? I don't know if this extra info helps answer the question, but my Dell is PC2100 266MHz CL2.5 DDR DIMM (ECC Registered)Double-Row.

[_=DeltaForce=_]

I have a 2 x Kingston PC3200, Crucial and PNY in my system right now and its working fine.. All are PC3200 and its detected in the bios without any problem.. I have an Asus mobo..

It should work but it does depends on the motherboard..

[pd123]

Deltaforce, Thank you for your reply. Upon further searching, I found the exact Kingston Part # from Computergiant.com for less than Crutial. The Kingston is $62.15 plus shipping, about $8. I think that is a great price, I will likely go for it, but first I am thinking if for about double the price, if I should go for the gig memory upgrade. I don't think I need that much memory, but I have to give it some thought.