is it an hp G62?? if so here is a list of compatible CPU's
Processor
NOTE:
All processor spare part kits include thermal material.
Description
Spare part number
Intel Arrandale i5–520M Processor (2.4 GHz, 3 MB total L3 cache, 1066 MHz)—Dual Core 35 W 594187–001
Intel Arrandale i5–540M Processor (2.53 GHz, 3 MB total L3 cache, 1066 MHz)—Dual core 35 W 594188–001
Intel Arrandale i3–330 Processor (2.13 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W (for
model 1.0 only)
597622–001
Intel Arrandale i3–350 Processor (2.26 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W 597623–001
Intel Arrandale i5–430 Processor (2.26 GHz, 3 MB total L3 cache, 1066 MHz)—Dual Core 35 W 597624-001
Intel Arrandale i3–370 Processor (2.4 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W 613584-001
Intel Arrandale i5–450 Processor (2.4 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W 613585-001
Pentium Arrandale P6000 Processor (1.86 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W 613586-001
Pentium Arrandale P6100 Processor (2.0 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W (for
model 1.1 only)
613587-001
Intel Arrandale i3–380 Processor (2.53 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W (for
model 1.1 only)
625823-001
Intel Arrandale i5–560 Processor (2.66–3.2 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W
(for model 1.1 only)
625824-001
Intel Arrandale i5–580 Processor (2.66–3.33 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W
(for model 1.1 only)
625825-001
Intel Pentium P6200 Processor (2.13 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W (for
model 1.1 only)
625831-001
Intel Core i5–460 Processor (2.53 GHz, 3 MB L3 cache, 1066 MHz)—Dual Core 35 W (for model
1.1 only)
this came from the service manual for the notebook
http://www.hp.com/ctg/Manual/c02542102.pdf
they are all dual core cpu's of similar clock speeds so my guess would be that you'll see minimal improvement with one of those i5 cpu's.