Greetings,

I have a Dell Dimension E510, and I want to upgrade some of the extra rams that I have. One of the ram is a Corsair 1GB DDR2 667 PC2-5300. I checked online for my computer spec and found that the comp supports 400-MHz and 533-MHz DDR2 (im not sure if i'm reading it right or not) here is the link: http://support.dell.com/support/edocs/SYSTEMS/dim5150/en/sm/specs1.htm#wp1052310
Is it possible to put the 1GB PC2-5300 (667 MHz) into E510? will it damage the motherboard?
Also, I want to mention that the E510 has a 1GB PC2 6400 DDR2 800 in it and it is running ok... I am a bit confused.. I thought the system doesn't support this type.

Another question is about my older machine Dell Dimension 4550, the problem is the ram that I have is 1GB DDR2 PC2 4200, It looks like Dimension 4550 only supports DDR ram. But I am not sure if i put in a DDR2 PC2-4200 would work or not. In the manual, it says maximum is 1GB, but it should be 2GB.
Dimension 4550 - http://support.dell.com/support/edocs/systems/dim4550/specs.htm
Is it possible to put a 1GB PC2-4200 (533 MHz) into Dimension 4550?