Can I replace a Core 2 Duo with a Core 2 Quad processor?
Can a Core 2 Quad processor be a direct replacement for a Core 2 Duo, given the same socket arrangement?
Solution 1:
If they have the same socket type (i.e. Socket 775) then a Core 2 Quad should work in place of a Core 2 Duo. At worst it may be a bios upgrade is necessary but other than that it should just work.
Solution 2:
This depends on your motherboard and your BIOS. We need more specifics to give you a good answer.