How can I determine how much RAM is being used on my laptop?

I have a HP Pavilion Notebook. It is less than 2 years old. I only use it for home use (internet, email, itunes music). I am frustrated at the speed of the machine. It seems to be getting slower all of the time while just doing normal windows tasks. I also frequently hear a grinding noise. Also, it takes so long to burn discs that I don't do that any longer. The machine has a CD-RW, but takes ages just to burn one disc and the machine often freezes when I try to do so.

The disc defrag says it doesn't need defraged (79% free space) and I run disc cleanup regularly. I have updated norton antivirus, lavasoft professional firewall, and ad aware pro.

Is there a way to tell how much of my RAM is being used to determine if that is the problem? Any other suggestions for diagnositcs? I'm sick of this slow machine!!!

How can I determine how much RAM is being used on my laptop?ariel

Those behaviors are absolutely abnormal,

First, I would check temperature. The noise can be from the fan, maybe it needs maintenance, as fans starts to fail after some years of heavy use. Usually they need lubricant, but the CPU needs to be cooled, if not, then it will slow down to protect itself from permanent damage. It could also be unstable.

If you've got an AMD processor like Sempron or Athlon 64, or Turion, you may want to check at what speed is it running, sometimes people are having problems with the Cool n Quiet driver, when its enabled in bios but not installed in windows.