You have a model D945GCL motherboard, and here are all of the supported processors:
It looks like the 960 (sSpec SL9K7 only) 3.6 Ghz processor is the best you can do. Notice that you have to have the BIOS support, which you can download from Intel for this
processor, if you can find it. Since this is an older processor it may be very difficult to find. You might try eBay and see if someone is selling one.
ASUS P8P800-MX Motherboar with Intel Celeron 2.66Ghz CPU and Fan, Intel Celeron 1.7Ghz Socket 478 Processor 1700Mhz/128/400/1.75v CPU SL69Z, Intel Celeron 1.7Ghz Socket 478 Processor 1700Mhz/128/400/1.75v CPU SL68C, MSI P4N Diamond motherboards for Intel Pentium, Duo, Celeron cpus, Intel® Celeron SLGLQ 2.20GHz 1M 800 CPU Processor, Acer Aspire 4315 Intel Celeron 1.73GHz 1M/533 laptop CPU processor SLA2G, Hp 399426-001 Cpu Intel Celeron M 1.46ghz, Intel Celeron E3300 (SLGU4) 2.5GHz Dual Core Socket LGA775 800MHz FSB 45nm CPU, Intel Celeron D SL96N 3.33GHz/512/533 Socket 775 CPU, Intel Celeron 633mhz Socket 370 Processor 633/128/66/1.65v SL3VS CPU, Intel Celeron D SL9KK 3.46GHz/512/533 Socket LGA775 CPU, Intel Celeron 1.3Ghz Socket 370 Processor 1300/256/100/1.5 SL6C7 CPU, lot of 5x Intel p4 and celeron CPU socket 478, Intel Celeron M 550 2.0 GHz / 1M / 533 MHz socket P CPU processor SLA2E TESTED, Intel Celeron M 360J Laptop CPu SL8ML 1.4GHz 400MHz 1MB Processor TESTED, Intel Mobile Celeron 800MHz/128/100 processor CPU SL584, + Intel D945GTP Motherboard w/ Celeron D 2.80GHz CPU & 512MB RAM, Intel DG35EC MicroATX LGA775 MB with Celeron Dual-Core 2.0 GHz CPU, ECS 661FX-M Socket 478 Motherboard + Intel Celeron D 2.66GHz CPU, Intel SL9BR Celeron D 3.06GHz 256KB 533MHz Desktop CPU Socket LGA775, Intel Celeron M 440 Laptop/Desktop CPU SL9KW 1.86GHz/533MHz/Socket M-Yonah, Intel Celeron 2.0ghz CPU Processor 550 SLA2E, Intel Celeron M 350 Laptop/Desktop CPU SL86L 1.3GHz/400MHz/Socket 479-Dothan, Intel Celeron D 340 Laptop/Desktop CPU SL7Q9 2.93GHz/533MHz/Socket 478-Prescott, Intel Celeron D 356 Laptop/Desktop CPU SL9KL 3.33GHz/533MHz/LGA 775/Socket T, Intel Celeron D 330 Laptop/Desktop CPU SL7DL 2.66GHz/533MHz/Socket 478-Prescott, Intel Celeron 2.50GHz Laptop/Desktop CPU SL6ZY 2.5GHz/400MHz/Socket 478, Intel Celeron 2.60GHz Laptop/Desktop CPU SL6VV 2.6GHz/400MHz/Socket 478, Intel Celeron 550 Laptop/Desktop CPU SLA2E 2GHz/533MHz/Socket P-Merom, Intel Celeron 540 Laptop/Desktop CPU SLA2F 1.86GHz/533MHz/Socket P-Merom, Intel Celeron 520 Laptop/Desktop CPU SL9WT 1.60GHz/533MHz/Socket M-Merom, Intel Celeron M 370 Laptop/Desktop CPU SL8MM 1.7GHz/400MHz/Socket 479-Dothan, Intel Celeron M 360 Laptop/Desktop CPU SL8ML 1.4GHz/400MHz/Socket 479-Dothan, Intel Celeron D 330 Laptop/Desktop CPU SL7DL 2.66GHz/533MHz/Socket 478-Prescott, Intel Celeron 2.70GHz Laptop/Desktop CPU SL77S 2.7GHz/400MHz/Socket 478, Intel Celeron SL6ZY 2.50GHz/128/400 Socket 478 CPU, Intel Celeron SL77S 2.70GHz/128/400 Socket 478 CPU, Intel Celeron D desktop cpu SL8H7, 436159-001 Hp Cpu Intel Celeron M Processor 430 - 1.73ghz (yonah 533mhz Front , 435766-001 Hp Cpu Intel Celeron M 430 - 1.73ghz (533mhz Front Side Bus Socket , Intel Celeron D SL8HD 3.06GHz/256/533 Socket LGA775 CPU, Intel Celeron M 1.6 GHz Laptop CPU SL8MN Ghz 400 Mhz, Intel Celeron Dual Core SLB6J T1600 1.66GHz 1M 667 CPU, INTEL CELERON 2.5 Ghz SOCKET 478 CPU SL6ZY Processor, Lot of 4 INTEL MOBILE CELERON 360 1.4 GHz CPU SL86K , INTEL Celeron CPU 2.3 GHz SL6XJ Socket 478, INTEL CELERON M CPU 420 -1.6GHZ SL8VZ LENOVO 3000 C200, Lot Of 2 Intel Celeron 1.46Ghz 1M 533Mhz SL8W2 CPU , Intel Celeron M 350 1.3GHz 400MHz CPU SL86L Lot of 2, Lot of 5 Intel Celeron D 2.66Ghz/256/533 SL7NV SOCKET 478 CPU,
