When the cost of the upgrade outweighs the benefit of the upgrade.
If the new one is the same size as the old, and you've got enough power supply to run it, it should work fine.
no, you cannot change it. The upgrade capabilities of the laptop is very few.
You can gain anywhere from 5-100% depending on how old your previous cpu was.
Before attempting to purchase any extra components, one should try to take the laptop apart. To improve the performance of an old laptop, one should upgrade the RAM, the Hard Drive, as well as the operating system.
I would recommend googling the the number on the old motherboard.
Most likely the need for an upgrade is as a result of slow processor, old mother board, small HDD, slow memory etc. An upgrade of memory (RAM to speed up computer) depends on the motherboard slots available. The fundamental issue is, does your mother board support latest upgrades on your system? Baulen
If you know a bit about hardware you could go out and purchase a new motherboard and CPU (you should be able to get an upgrade kit) and then install it yourself by pulling the computer apart and replacing the old one, however if you don't know how to do this then i recommend taking it to an IT professional to do if for you, They will usually give you a warrenty for it and this eliminates the chances of you voiding your existing warrenty so it is definetly worth the extra cost if you don't want to risk it. If you wish to do it yourself then simply remove all PCI or similar cards from your motherboard, IDE, Sata, etc cables from motherboard and the power, reset light, etc cables. Then unskrew the old motherboard and put in the new one (somtimes you may have to remove the powersupply to be able to get into it.) Then reattach the devices into the new motherboard carful to put it all back into the same places you took them out and follow the motherboard manual if you have any troubles working out what goes where. After this install the new drivers which came with the motherboard and your good to go ;). However you cannot just replace the CPU and not the motherboard if the new CPU you have is not compatible with your current motherboard. In most cases when upgrading you need a new motherboard too.
You will at least need a new motherboard. The rest of the hardware in the Pentium II is probably so old that I would buy a new computer instead which has all new hardware.
Yes, it is possible to replace your motherboard with new one. Just make sure that your new motherboard fits in your computer, and that it support all of the hardware you had on your old motherboard.
You cannot download any software to increase the speed of a USB port. the old USB ports are 1.1 compared to the new 2.0 The only way you can upgrade them is by physically replacing them by 2.0 ports, which is not advised. It makes more sense to buy either a new motherboard or system
You'll be better off replacing the entire computer. The motherboard from your P4 CPU chip certainly will not work with a new quad-core CPU. You'll probably need to add more RAM, and the RAM simms on your old PC probably would not be compatible with the new motherboard. You probably need a bigger hard drive, and it's certainly time to purchase a new power supply. About the only thing that might be transferable to the new PC would be your optical drive - and if your old PC had a CD-ROM, you'll probably want to upgrade to a DVD writer.