how many cores is your CPU, also what model CPU do you have?
to check Model:
Start > Right Click on Computer> Go Properties > Check Processor
It should say something like "Procesor: Intel/AMD blah blah blah"
To check Amount of cores: the best way to check is to do:
Ctrl + Shift + Esc (windows 7/vista) or Ctrl + Alt + Del (For XP)
and then click Performance, and how many boxes it has, is how many cores.