How important is 3rd generation vs. 4rth generation Intel?

I hate my present computer and want to get a laptop that will have good processing for years to come.

I don't know anything about the significance of which Intel generation. Is 4rth generation necessarily better than 3rd generation?



Windows XP
Home Edition
Version 2002
32-bit
Service Pack 3

Dell DIMENSION DIM2400
Intel(R)
Pentium(R) 4 CPU 2.66GHz
x86 Family 15 Model 2 Stepping 9
2.05 GB of RAM
Graphics Card: Intel(R) 82845G/GL/GE/PE/GV
Graphics Controller, 64 Mb
Hard Drive Size 114.4GB
Free Space was 35.8GB; now under 20GB because after backing up My Documents on Google Drive, Google Drive has duplicated the whole darn thing on my hard drive
Motherboard: Dell Computer Corp., 0G1548
Antivirus : Webroot Internet Security