Options to upgrade from celeron 420 1 6Ghz to higher cpu

OK really need to know what motherboard you have to know what you can upgrade too. Download CPU-Z from www.cpuid.com and tell us what the mainboard is. Also There i no such thing as DDR2 2ghz Its either DDR2 667 800 or 1066 my guess would be its 667. So figure out your motherboard and post back.
 


@ SAAIELLO: The cpu you linked is NOT the conroe core 2 duo E6600; it is actually the wolfdale based pentium E6600 (which will not work with the OP's mobo).

@bonsev39: On newegg, the fastest cpu that will work with your mobo is the Celeron Dual Core E1600 (2.4 GHz) for $62. It gives you a ~50% speed increase (plus an additional core) over your current cpu.
http://www.newegg.com/Product/Product.aspx?Item=N82E16819116092