800 is the actual I/0 bus clock speed in MHz; that's correct. Most people get the clock speed confused with the data rate (which is always advertised in MHz, but the data rate is actually in MT/s - or megatransfers per second). The confusion is really the fault of how the memory is advertised.
ANYWAY
Are you sure your system supports 4 GB modules? And one other compatibility thing to check: Is it high density or low density memory (and which does your laptop support)?
Your CPU usage seems fairly normal for idle (0% would be better, but if you have a lot of programs installed, 5% - 20% is not uncommon). Your RAM usage for idle is a little high, but then again, it's only 2 GB. Windows caches some of that RAM and your programs in the background are probably eating up some of it too.