Hello and Welcome to Windows7forums..
Unfortunately by the sounds of it your going to have to upgrade your CPU if you want a big performance gain.. Programs like Aibooster can only push a CPU so far.. Especially AMD CPU's.. Don't get me wrong, I'm an AMD man and always have been but the first gen X2 proc's aren't that great at being pushed beyond their normal limits..
If upgrading your CPU isn't an option at this point in time, maybe you could think about overclocking other components like your GPU and RAM.. Just be careful though, overclocking is a great thing but if done the wrong way it can lead to disaster..
Also, make sure your PSU is up for the challenge before you start tweaking too much..
*I'm going to move this thread to the Windows 7 Support Section*