Reformatted, now my computer is even slower

[NoComputerExperienceGirl]

I'm not quite sure if this is even the right section to post this. I didn't know where to put it since I don't know which piece of hardware of mine is even what's to blame. My computer was slow, and I recently added another harddrive and reformatted, and now it's even slower than before. I can't run any of my steam games, they just lag like crazy.
I've updated my graphics drivers, but I don't know what else to do.
I admit my knowledge of computers is limited, so I hope people will be patient with helping me out. One day I plan on completely rebuilding my computer with all new parts, but being as I'm jobless at the moment I hope there are other fixes.

Also I'm running Vista 64x, and I can't seem to get CCC to work properly. It works in almost all ways, except when I right click the icon in the right corner, it doesn't do anything,

 

[NoComputerExperienceGirl]

Reinstall ALL the drivers possible

Graphics Card-Download the latest from AMD/Nvidia's website
Motherboard-Latest from ur vendor's website
and do u have 4GB ++ of RAM ?

I do but the motherboard only recognizes 2.5GB of it.

I'm not even sure what motherboard I have to even get an update for it.