I just bought (not built) a new PC. I asked for DDR2 800 MHz RAM because I believed that the motherboard supports it. But when I checked the BIOS I find that it's running at 667MHz. Can I just set it to 800? If it refuses to boot, will I have to mess with a jumper? If this is too complicated for me (no laughjing please) then I'll have to get the builder to change it. I don't want a PC that won't boot! Any help is much appreciated.