1GB eka 800mhz da... 667 da. if not work after changing slots even.. Change bios to 667.. and try.
As manuals Support upto 2GB per 1 slot. 4GB is the Maximum.
Make sure your mother board compatible with dual channel.
Dual channel is a feature of the motherboard, not the memory. As long as you have a matched pair of memory sticks & they're placed in the proper two slots, dual channel mode *should* automatically enable. If you have a cheaper board that only has two memory slots, it's a no-brainer.
You should always manually configure your memory settings in the BIOS, especially the voltage. According to the JEDEC standard, all DDR2 memory is supposed to run at 1.8v, however, most of the so-called 'performance memory' can require voltage as high as 2.2 - 2.4v. Check the documentation that came with your RAM or the sticker on the RAM itself. If the timings & voltage isn't listed, go to the Kingston website & look it up, then set your BIOS accordingly.
Best of luck