Some Acer Apire 3680 are still having the BIOS V1.3502 which known to have some to problem related to memory, processor Core 2 Duo support and Windows Vista Operating System.
Acer has release new BIOS V1.3505 which resolve above problems.
For you who want to upgrade your processor to Core 2 Duo, then you must do BIOS Upgrade to V1.3505.
It is so simple to upgrade the BIOS, you just download the BIOS update and run the swinflash.exe.
You can download the BIOS upgrade here.