i have 512 pc2100(highest MB supports). i am going to double my ram, but i want to get pc3200(for when i upgrade my mobo). i know it will only run at 266mhz when installed with my pc2100 stick. what i want to know, is if it will actually work with my motherboard, since it only supports up to pc2100. motherboard is msi kt266(non pro, quite old).

By rights it should work. The pc3200 will clock down to 266 and operate at that frequency. Something you may want to keep an eye out for is the cas latency timing of the 2 ram modules, and see if you can match them up. Most pc2100 modules were cas 2.5 but there are some pc3200 modules which are cas 3.0 try and match the old and new modules with the same latency timing. This should reduce chnaces of incompatability. Regards IF IT AINT BROKE, DONT FIX IT