Please Help Me To Upgrade Core 2 Duo E6x00 To Core 2 Quad Q6xx0 Asus Ipibl La

Motherboard description
Motherboard manufacturer's name: ASUS IPIBL-LA
HP/Compaq name: Berkeley-GL8E
CPU/Processor
Socket: 775
Supports the following processors:
Intel Core 2 Quad Q6xx0 with Quad Core technology
Core 2 Duo E6x00
Core 2 Duo E4x00

I have changed the processor already but the computer doen't recognize the Quad processor. Is there something I must do on the ASUS IPIBL-LA motherboard when changing the processor.