ok so i am building a new rig soon and i am pritty sure what i want to get. i was going to get 2 sticks of 2gb ddr2. however, i only have a 32 bit version of windows xp (taken from old computer which is dead). now i know 32 bits can only have 3 gigs of memory. so my question is can you have the system use 1 full stick of ram and then only one gig on the other( i don't think so but that is why i am checking). or do i just use 1 stick till i get vista 64bit in a year or 2?

thanks

Don't worry about it. Both modules will run in dual channel. Depending on the rest of your system (mostly the video card) you will have more than 3 Gigabyte.