Well this is your motherboard.
Motherboard Specifications, P5BW-LA (Basswood) HP Pavilion Media Center TV m7684n Desktop PC - HP Customer Care (United States - English)
Here are the cpus that it supports:
* Socket: 775
* Supports the following processors:
o Intel Core Duo E6x00 with Dual Core technology (Conroe core)
o Pentium D 9x0 series Dual Core (Presler)
o Pentium D 8xx series (Smithfield)
o Pentium 4 6x1 series (Cedar Mill core)
o Pentium 4 6xx (Prescott core)
o Pentium 4 5xx (Prescott core)
o Pentium 4 LGA-775 HT (Prescott core)
The best it supports are the e6x00 (conroe 65nm)
The Q9650 is a Yorkfield 45nm and not supported by that board.