Hi!. I got a not so new Dell optiplex 745 with a old Intel Pentium 4 530 @3.00Ghz with 1gb of sYstem RAM, a 80gb seagate hard drive, a 305w power supply And integrated intel gma 3000 graphics, my question is, Can i replace the old Pentium 4 that is 90nm with a Pentium e5500 or a Core 2 Duo e6750 that are 45nm? also, i will buy a geforce gt430 and a 2gb dual channel ddr2 memory. does the power supply support these three components? also is this a good computer or should i buy a motherboard and install everything from the start?