Download this:

After you have downloaded the file, put it in your NFSU2 folder. Create a shortcut of the imagecfg.exe and open its properties(rightclick+bottom option). Type " -a 0x1 SPEED2.EXE"(without the quotation marks) after the ".../imagecfg.exe". After you have run this, NFSU2 should be running off of the CPU1 from then on. This will work with every game. For more documentation see: