Hi there,
Your motherboard supports the...
Socket 775
So when looking for a new CPU, make sure that it has Socket 775 in it's description / name.
Only CPU's that support socket 775 will work with your motherboard.
Examples of CPU's that your motherboard supports:
Intel Pentium 4 (2.60 - 3.80 GHz)
Intel Celeron D (2.53 - 3.60 GHz)
Intel Pentium 4 Extreme Edition
(3.20 - 3.73 GHz)
Intel Pentium D (2.66 - 3.60 GHz)
Pentium Extreme Edition
(3.20 - 3.73 GHz)
Pentium Dual-Core (1.40 - 3.33 GHz)
Intel Core 2 Duo (1.60 - 3.33 GHz)
Intel Core 2 Extreme (2.66 - 3.20 GHz)
Intel Core 2 Quad (2.33 - 3.00 GHz)
Intel Xeon (1.86-3.40 GHz)
Intel Celeron (1.60 - 2.40 GHz)
Reference:
https://en.wikipedia.org/wiki/LGA_775
http://www.cpu-upgrade.com/mb-MSI/P7N_SLI_(MS-7380).html